1=head1 NAME
2
3DBI::Changes - List of significant changes to the DBI
4
5=encoding UTF-8
6
7=cut
8
9=head2 Changes in DBI 1.643 - ...
10
11    Fix memory corruption in XS functions when Perl stack is reallocated
12        thanks to Pali
13    Fix calling dbd_db_do6 API function
14        thanks to Pali
15    Fix potentially calling newSV(0) in malloc_using_sv()
16        thanks to Pali
17    Fix order of XS preparse() ps_accept and ps_return argument names
18        thanks to Petr Písař
19    Fix a potential NULL profile dereference in dbi_profile()
20        thanks to Petr Písař
21    Fix a buffer overflow on an overlong DBD class name
22        thanks to Petr Písař
23
24    Remove remnants of support for perl <= v5.8.0
25        thanks to Pali and H.Merijn Brand
26    Update Devel::PPPort and remove redundant compatibility macros
27        thanks to Pali and H.Merijn Brand
28
29    Correct minor typo in documentation
30        thanks to Mohammad Anwar
31    Correct documentation introducing $dbh->selectall_array()
32        thanks to Pali
33    Introduce select and do wrappers earlier in the documentation
34        thanks to Dan Book
35    Mark as deprecated old API functions which overflow or are affected by
36        Unicode issues, thanks to Pali
37
38    Add new attribute RaiseWarn, similar to RaiseError,
39        thanks to Pali
40
41=head2 Changes in DBI 1.642 - 28th October 2018
42
43    Fix '.' in @INC for proxy test under parallel load
44        thanks to H.Merijn Brand.
45    Fix driver-related croak() in DBI->connect to report the original DSN
46        thanks to maxatome #67
47
48    Introduce a new statement DBI method $sth->last_insert_id()
49        thanks to pali #64
50    Allow to call $dbh->last_insert_id() method without arguments
51        thanks to pali #64
52    Added a new XS API function variant dbd_db_do6()
53        thanks to Pali #61
54
55    Fix misprints in doc of selectall_hashref
56        thanks to Perlover #69
57    Remove outdated links to DBI related training resources. RT#125999
58
59=head2 Changes in DBI 1.641 - 19th March 2018
60
61    Remove dependency on Storable 2.16 introduced in DBI 1.639
62        thanks to Ribasushi #60
63    Avoid compiler warnings in Driver.xst #59
64        thanks to pali #59
65
66=head2 Changes in DBI 1.640 - 28th January 2018
67
68    Fix test t/91_store_warning.t for perl 5.10.0
69        thanks to pali #57
70
71    Add Perl 5.10.0 and 5.8.1 specific versions to Travis testing
72        thanks to pali #57
73    Add registration of mariadb_ prefix for new DBD::MariaDB driver
74        thanks to pali #56
75
76=head2 Changes in DBI 1.639 - 28th December 2017
77
78    Fix UTF-8 support for warn/croak calls within DBI internals,
79        thanks to pali #53
80    Fix dependency on Storable for perl older than 5.8.9,
81        thanks to H.Merijn Brand.
82
83    Add DBD::Mem driver, a pure-perl in-memory driver using DBI::DBD::SqlEngine,
84        thanks to Jens Rehsack #42
85
86    Corrected missing semicolon in example in documentation,
87        thanks to pali #55
88
89=head2 Changes in DBI 1.637 - 16th August 2017
90
91    Fix use of externally controlled format string (CWE-134) thanks to pali #44
92        This could cause a crash if, for example, a db error contained a %.
93        https://cwe.mitre.org/data/definitions/134.html
94    Fix extension detection for DBD::File related drivers
95    Fix tests for perl without dot in @INC RT#120443
96    Fix loss of error message on parent handle, thanks to charsbar #34
97    Fix disappearing $_ inside callbacks, thanks to robschaber #47
98    Fix dependency on Storable for perl older than 5.8.9
99
100    Allow objects to be used as passwords without throwing an error, thanks to demerphq #40
101    Allow $sth NAME_* attributes to be set from Perl code, re #45
102    Added support for DBD::XMLSimple thanks to nigelhorne #38
103
104    Documentation updates:
105    Improve examples using eval to be more correct, thanks to pali #39
106    Add cautionary note to prepare_cached docs re refs in %attr #46
107    Small POD changes (Getting Help -> Online) thanks to openstrike #33
108    Adds links to more module names and fix typo, thanks to oalders #43
109    Typo fix thanks to bor #37
110
111=head2 Changes in DBI 1.636 - 24th April 2016
112
113    Fix compilation for threaded perl <= 5.12 broken in 1.635 RT#113955
114    Revert change to DBI::PurePerl DESTROY in 1.635
115    Change t/16destroy.t to avoid race hazard RT#113951
116    Output perl version and archname in t/01basics.t
117    Add perl 5.22 and 5.22-extras to travis-ci config
118
119=head2 Changes in DBI 1.635 - 24th April 2016
120
121    Fixed RaiseError/PrintError for UTF-8 errors/warnings. RT#102404
122    Fixed cases where ShowErrorStatement might show incorrect Statement RT#97434
123    Fixed DBD::Gofer for UTF-8-enabled STDIN/STDOUT
124        thanks to mauke PR#32
125    Fixed fetchall_arrayref({}) behavior with no columns
126        thanks to Dan McGee PR#31
127    Fixed tied CachedKids ref leak in attribute cache by weakening
128        thanks to Michael Conrad RT#113852
129    Fixed "panic: attempt to copy freed scalar" upon commit() or rollback()
130        thanks to fbriere for detailed bug report RT#102791
131    Ceased to ignore DESTROY of outer handle in DBI::PurePerl
132    Treat undef in DBI::Profile Path as string "undef"
133        thanks to fREW Schmidt RT#113298
134    Fix SQL::Nano parser to ignore trailing semicolon
135        thanks to H.Merijn Brand.
136
137    Added @ary = $dbh->selectall_array(...) method
138        thanks to Ed Avis RT#106411
139    Added appveyor support (Travis like CI for windows)
140        thanks to mbeijen PR#30
141
142    Corrected spelling errors in pod
143        thanks to Gregor Herrmann RT#107838
144    Corrected and/or removed broken links to SQL standards
145        thanks to David Pottage RT#111437
146    Corrected doc example to use dbi: instead of DBI: in DSN
147        thanks to Michael R. Davis RT#101181
148    Removed/updated broken links in docs
149        thanks to mbeijen PR#29
150    Clarified docs for DBI::hash($string)
151    Removed the ancient DBI::FAQ module RT#102714
152    Fixed t/pod.t to require Test::Pod >= 1.41 RT#101769
153
154This release was developed at the Perl QA Hackathon 2016
155L<http://act.qa-hackathon.org/qa2016/>
156which was made possible by the generosity of many sponsors:
157
158L<https://www.fastmail.com> FastMail,
159L<https://www.ziprecruiter.com> ZipRecruiter,
160L<http://www.activestate.com> ActiveState,
161L<http://www.opusvl.com> OpusVL,
162L<https://www.strato.com> Strato,
163L<http://www.surevoip.co.uk> SureVoIP,
164L<http://www.cv-library.co.uk> CV-Library,
165L<https://www.iinteractive.com/> Infinity,
166L<https://opensource.careers/perl-careers/> Perl Careers,
167L<https://www.mongodb.com> MongoDB,
168L<https://www.thinkproject.com> thinkproject!,
169L<https://www.dreamhost.com/> Dreamhost,
170L<http://www.perl6.org/> Perl 6,
171L<http://www.perl-services.de/> Perl Services,
172L<https://www.evozon.com/> Evozon,
173L<http://www.booking.com> Booking,
174L<http://eligo.co.uk> Eligo,
175L<http://www.oetiker.ch/> Oetiker+Partner,
176L<http://capside.com/en/> CAPSiDE,
177L<https://www.procura.nl/> Procura,
178L<https://constructor.io/> Constructor.io,
179L<https://metacpan.org/author/BABF> Robbie Bow,
180L<https://metacpan.org/author/RSAVAGE> Ron Savage,
181L<https://metacpan.org/author/ITCHARLIE> Charlie Gonzalez,
182L<https://twitter.com/jscook2345> Justin Cook.
183
184=head2 Changes in DBI 1.634 - 3rd August 2015
185
186    Enabled strictures on all modules (Jose Luis Perez Diez) #22
187        Note that this might cause new exceptions in existing code.
188        Please take time for extra testing before deploying to production.
189    Improved handling of row counts for compiled drivers and enable them to
190        return larger row counts (IV type) by defining new *_iv macros.
191    Fixed quote_identifier that was adding a trailing separator when there
192        was only a catalog (Martin J. Evans)
193
194    Removed redundant keys() call in fetchall_arrayref with hash slice (ilmari) #24
195    Corrected pod xref to Placeholders section (Matthew D. Fuller)
196    Corrected pod grammar (Nick Tonkin) #25
197
198    Added support for tables('', '', '', '%') special case (Martin J. Evans)
199    Added support for DBD prefixes with numbers (Jens Rehsack) #19
200    Added extra initializer for DBI::DBD::SqlEngine based DBD's (Jens Rehsack)
201    Added Memory Leaks section to the DBI docs (Tim)
202    Added Artistic v1 & GPL v1 LICENSE file (Jose Luis Perez Diez) #21
203
204=head2 Changes in DBI 1.633 - 11th Jan 2015
205
206    Fixed selectrow_*ref to return undef on error in list context
207        instead if an empty list.
208    Changed t/42prof_data.t more informative
209    Changed $sth->{TYPE} to be NUMERIC in DBD::File drivers as per the
210        DBI docs. Note TYPE_NAME is now also available. [H.Merijn Brand]
211    Fixed compilation error on bleadperl due DEFSV no longer being an lvalue
212        [Dagfinn Ilmari Mannsåker]
213
214    Added docs for escaping placeholders using a backslash.
215    Added docs for get_info(9000) indicating ability to escape placeholders.
216    Added multi_ prefix for DBD::Multi (Dan Wright) and ad2_ prefix for
217        DBD::AnyData2
218
219=head2 Changes in DBI 1.632 - 9th Nov 2014
220
221    Fixed risk of memory corruption with many arguments to methods
222        originally reported by OSCHWALD for Callbacks but may apply
223        to other functionality in DBI method dispatch RT#86744.
224    Fixed DBD::PurePerl to not set $sth->{Active} true by default
225        drivers are expected to set it true as needed.
226    Fixed DBI::DBD::SqlEngine to complain loudly when prerequite
227        driver_prefix is not fulfilled (RT#93204) [Jens Rehsack]
228    Fixed redundant sprintf argument warning RT#97062 [Reini Urban]
229    Fixed security issue where DBD::File drivers would open files
230        from folders other than specifically passed using the
231        f_dir attribute RT#99508 [H.Merijn Brand]
232
233    Changed delete $h->{$key} to work for keys with 'private_' prefix
234        per request in RT#83156. local $h->{$key} works as before.
235
236    Added security notice to DBD::Proxy and DBI::ProxyServer because they
237        use Storable which is insecure. Thanks to ppisar@redhat.com RT#90475
238    Added note to AutoInactiveDestroy docs strongly recommending that it
239        is enabled in all new code.
240
241=head2 Changes in DBI 1.631 - 20th Jan 2014
242
243NOTE: This release changes the handle passed to Callbacks from being an 'inner'
244handle to being an 'outer' handle. If you have code that makes use of Callbacks,
245ensure that you understand what this change means and review your callback code.
246
247    Fixed err_hash handling of integer err RT#92172 [Dagfinn Ilmari]
248    Fixed use of \Q vs \E in t/70callbacks.t
249
250    Changed the handle passed to Callbacks from being an 'inner'
251        handle to being an 'outer' handle.
252
253    Improved reliability of concurrent testing
254        PR#8 [Peter Rabbitson]
255    Changed optional dependencies to "suggest"
256        PR#9 [Karen Etheridge]
257    Changed to avoid mg_get in neatsvpv during global destruction
258        PR#10 [Matt Phillips]
259
260=head2 Changes in DBI 1.630 - 28th Oct 2013
261
262NOTE: This release enables PrintWarn by default regardless of $^W.
263Your applications may generate more log messages than before.
264
265    Fixed err for new drh to be undef not to 0 [Martin J. Evans]
266    Fixed RT#83132 - moved DBIstcf* constants to util
267        export tag [Martin J. Evans]
268    PrintWarn is now triggered by warnings recorded in methods like STORE
269        that don't clear err RT#89015 [Tim Bunce]
270
271    Changed tracing to no longer show quote and quote_identifier calls
272        at trace level 1.
273    Changed DBD::Gofer ping while disconnected set_err from warn to info.
274    Clarified wording of log message when err is cleared.
275    Changed bootstrap to use $XS_VERSION RT#89618 [Andreas Koenig]
276
277    Added connect_cached.connected Callback PR#3 [David E. Wheeler]
278
279    Clarified effect of refs in connect_cached attributes [David E. Wheeler]
280    Extended ReadOnly attribute docs for when the driver cannot
281      ensure read only [Martin J. Evans]
282    Corrected SQL_BIGINT docs to say ODBC value is used PR#5 [ilmari]
283
284There was no DBI 1.629 release.
285
286=head2 Changes in DBI 1.628 - 22nd July 2013
287
288    Fixed missing fields on partial insert via DBI::DBD::SqlEngine
289        engines (DBD::CSV, DBD::DBM etc.) [H.Merijn Brand, Jens Rehsack]
290    Fixed stack corruption on callbacks RT#85562 RT#84974 [Aaron Schweiger]
291    Fixed DBI::SQL::Nano_::Statement handling of "0" [Jens Rehsack]
292    Fixed exit op precedence in test RT#87029 [Reni Urban]
293
294    Added support for finding tables in multiple directories
295        via new DBD::File f_dir_search attribute [H.Merijn Brand]
296    Enable compiling by C++ RT#84285 [Kurt Jaeger]
297
298    Typo fixes in pod and comment [David Steinbrunner]
299    Change DBI's docs to refer to git not svn [H.Merijn Brand]
300    Clarify bind_col TYPE attribute is sticky [Martin J. Evans]
301    Fixed reference to $sth in selectall_arrayref docs RT#84873
302    Spelling fixes [Ville Skyttä]
303    Changed $VERSIONs to hardcoded strings [H.Merijn Brand]
304
305=head2 Changes in DBI 1.627 - 16th May 2013
306
307    Fixed VERSION regression in DBI::SQL::Nano [Tim Bunce]
308
309=head2 Changes in DBI 1.626 - 15th May 2013
310
311    Fixed pod text/link was reversed in a few cases RT#85168
312        [H.Merijn Brand]
313
314    Handle aliasing of STORE'd attributes in DBI::DBD::SqlEngine
315        [Jens Rehsack]
316
317    Updated repository URI to git [Jens Rehsack]
318
319    Fixed skip() count arg in t/48dbi_dbd_sqlengine.t [Tim Bunce]
320
321=head2 Changes in DBI 1.625 (svn r15595) 28th March 2013
322
323  Fixed heap-use-after-free during global destruction RT#75614
324    thanks to Reini Urban.
325  Fixed ignoring RootClass attribute during connect() by
326    DBI::DBD::SqlEngine reported in RT#84260 by Michael Schout
327
328=head2 Changes in DBI 1.624 (svn r15576) 22nd March 2013
329
330  Fixed Gofer for hash randomization in perl 5.17.10+ RT#84146
331
332  Clarify docs for can() re RT#83207
333
334=head2 Changes in DBI 1.623 (svn r15547) 2nd Jan 2013
335
336  Fixed RT#64330 - ping wipes out errstr (Martin J. Evans).
337  Fixed RT#75868 - DBD::Proxy shouldn't call connected() on the server.
338  Fixed RT#80474 - segfault in DESTROY with threads.
339  Fixed RT#81516 - Test failures due to hash randomisation in perl 5.17.6
340    thanks to Jens Rehsack and H.Merijn Brand and feedback on IRC
341  Fixed RT#81724 - Handle copy-on-write scalars (sprout)
342  Fixed unused variable / self-assignment compiler warnings.
343  Fixed default table_info in DBI::DBD::SqlEngine which passed NAMES
344    attribute instead of NAME to DBD::Sponge RT72343 (Martin J. Evans)
345
346  Corrected a spelling error thanks to Chris Sanders.
347  Corrected typo in DBI->installed_versions docs RT#78825
348    thanks to Jan Dubois.
349
350  Refactored table meta information management from DBD::File into
351    DBI::DBD::SqlEngine (H.Merijn Brand, Jens Rehsack)
352  Prevent undefined f_dir being used in opendir (H.Merijn Brand)
353
354  Added logic to force destruction of children before parents
355    during global destruction. See RT#75614.
356  Added DBD::File Plugin-Support for table names and data sources
357    (Jens Rehsack, #dbi Team)
358  Added new tests to 08keeperr for RT#64330
359    thanks to Kenichi Ishigaki.
360  Added extra internal handle type check, RT#79952
361    thanks to Reini Urban.
362  Added cubrid_ registered prefix for DBD::cubrid, RT#78453
363
364  Removed internal _not_impl method (Martin J. Evans).
365
366  NOTE: The "old-style" DBD::DBM attributes 'dbm_ext' and 'dbm_lockfile'
367    have been deprecated for several years and their use will now generate
368    a warning.
369
370=head2 Changes in DBI 1.622 (svn r15327) 6th June 2012
371
372  Fixed lack of =encoding in non-ASCII pod docs. RT#77588
373
374  Corrected typo in DBI::ProfileDumper thanks to Finn Hakansson.
375
376=head2 Changes in DBI 1.621 (svn r15315) 21st May 2012
377
378  Fixed segmentation fault when a thread is created from
379    within another thread RT#77137, thanks to Dave Mitchell.
380  Updated previous Changes to credit Booking.com for sponsoring
381    Dave Mitchell's recent DBI optimization work.
382
383=head2 Changes in DBI 1.620 (svn r15300) 25th April 2012
384
385  Modified column renaming in fetchall_arrayref, added in 1.619,
386    to work on column index numbers not names (an incompatible change).
387  Reworked the fetchall_arrayref documentation.
388  Hash slices in fetchall_arrayref now detect invalid column names.
389
390=head2 Changes in DBI 1.619 (svn r15294) 23rd April 2012
391
392  Fixed the connected method to stop showing the password in
393    trace file (Martin J. Evans).
394  Fixed _install_method to set CvFILE correctly
395    thanks to sprout RT#76296
396  Fixed SqlEngine "list_tables" thanks to David McMath
397    and Norbert Gruener. RT#67223 RT#69260
398
399  Optimized DBI method dispatch thanks to Dave Mitchell.
400  Optimized driver access to DBI internal state thanks to Dave Mitchell.
401  Optimized driver access to handle data thanks to Dave Mitchell.
402    Dave's work on these optimizations was sponsored by Booking.com.
403  Optimized fetchall_arrayref with hash slice thanks
404    to Dagfinn Ilmari Mannsåker. RT#76520
405  Allow renaming columns in fetchall_arrayref hash slices
406    thanks to Dagfinn Ilmari Mannsåker. RT#76572
407  Reserved snmp_ and tree_ for DBD::SNMP and DBD::TreeData
408
409=head2 Changes in DBI 1.618 (svn r15170) 25rd February 2012
410
411  Fixed compiler warnings in Driver_xst.h (Martin J. Evans)
412  Fixed compiler warning in DBI.xs (H.Merijn Brand)
413  Fixed Gofer tests failing on Windows RT74975 (Manoj Kumar)
414  Fixed my_ctx compile errors on Windows (Dave Mitchell)
415
416  Significantly optimized method dispatch via cache (Dave Mitchell)
417  Significantly optimized DBI internals for threads (Dave Mitchell)
418    Dave's work on these optimizations was sponsored by Booking.com.
419  Xsub to xsub calling optimization now enabled for threaded perls.
420  Corrected typo in example in docs (David Precious)
421  Added note that calling clone() without an arg may warn in future.
422  Minor changes to the install_method() docs in DBI::DBD.
423  Updated dbipport.h from Devel::PPPort 3.20
424
425=head2 Changes in DBI 1.617 (svn r15107) 30th January 2012
426
427  NOTE: The officially supported minimum perl version will change
428  from perl 5.8.1 (2003) to perl 5.8.3 (2004) in a future release.
429  (The last change, from perl 5.6 to 5.8.1, was announced
430  in July 2008 and implemented in DBI 1.611 in April 2010.)
431
432  Fixed ParamTypes example in the pod (Martin J. Evans)
433  Fixed the definition of ArrayTupleStatus and remove confusion over
434    rows affected in list context of execute_array (Martin J. Evans)
435  Fixed sql_type_cast example and typo in errors (Martin J. Evans)
436  Fixed Gofer error handling for keeperr methods like ping (Tim Bunce)
437  Fixed $dbh->clone({}) RT73250 (Tim Bunce)
438  Fixed is_nested_call logic error RT73118 (Reini Urban)
439
440  Enhanced performance for threaded perls (Dave Mitchell, Tim Bunce)
441    Dave's work on this optimization was sponsored by Booking.com.
442  Enhanced and standardized driver trace level mechanism (Tim Bunce)
443  Removed old code that was an inneffective attempt to detect
444    people doing DBI->{Attrib}.
445  Clear ParamValues on bind_param param count error RT66127 (Tim Bunce)
446  Changed DBI::ProxyServer to require DBI at compile-time RT62672 (Tim Bunce)
447
448  Added pod for default_user to DBI::DBD (Martin J. Evans)
449  Added CON, ENC and DBD trace flags and extended 09trace.t (Martin J. Evans)
450  Added TXN trace flags and applied CON and TXN to relevant methods (Tim Bunce)
451  Added some more fetchall_arrayref(..., $maxrows) tests (Tim Bunce)
452  Clarified docs for fetchall_arrayref called on an inactive handle.
453  Clarified docs for clone method (Tim Bunce)
454  Added note to DBI::Profile about async queries (Marcel Grünauer).
455  Reserved spatialite_ as a driver prefix for DBD::Spatialite
456  Reserved mo_ as a driver prefix for DBD::MO
457  Updated link to the SQL Reunion 95 docs, RT69577 (Ash Daminato)
458  Changed links for DBI recipes. RT73286 (Martin J. Evans)
459
460=head2 Changes in DBI 1.616 (svn r14616) 30th December 2010
461
462  Fixed spurious dbi_profile lines written to the log when
463    profiling is enabled and a trace flag, like SQL, is used.
464  Fixed to recognize SQL::Statement errors even if instantiated
465    with RaiseError=0 (Jens Rehsack)
466  Fixed RT#61513 by catching attribute assignment to tied table access
467    interface (Jens Rehsack)
468  Fixing some misbehavior of DBD::File when running within the Gofer
469    server.
470  Fixed compiler warnings RT#62640
471
472  Optimized connect() to remove redundant FETCH of \%attrib values.
473  Improved initialization phases in DBI::DBD::SqlEngine (Jens Rehsack)
474
475  Added DBD::Gofer::Transport::corostream. An experimental proof-of-concept
476    transport that enables asynchronous database calls with few code changes.
477    It enables asynchronous use of DBI frameworks like DBIx::Class.
478
479  Added additional notes on DBDs which avoid creating a statement in
480    the do() method and the effects on error handlers (Martin J. Evans)
481  Adding new attribute "sql_dialect" to DBI::DBD::SqlEngine to allow
482    users control used SQL dialect (ANSI, CSV or AnyData), defaults to
483    CSV (Jens Rehsack)
484  Add documentation for DBI::DBD::SqlEngine attributes (Jens Rehsack)
485  Documented dbd_st_execute return (Martin J. Evans)
486  Fixed typo in InactiveDestroy thanks to Emmanuel Rodriguez.
487
488=head2 Changes in DBI 1.615 (svn r14438) 21st September 2010
489
490  Fixed t/51dbm_file for file/directory names with whitespaces in them
491    RT#61445 (Jens Rehsack)
492  Fixed compiler warnings from ignored hv_store result (Martin J. Evans)
493  Fixed portability to VMS (Craig A. Berry)
494
495=head2 Changes in DBI 1.614 (svn r14408) 17th September 2010
496
497  Fixed bind_param () in DBI::DBD::SqlEngine (rt#61281)
498  Fixed internals to not refer to old perl symbols that
499    will no longer be visible in perl >5.13.3 (Andreas Koenig)
500    Many compiled drivers are likely to need updating.
501  Fixed issue in DBD::File when absolute filename is used as table name
502    (Jens Rehsack)
503  Croak manually when file after tie doesn't exists in DBD::DBM
504    when it have to exists (Jens Rehsack)
505  Fixed issue in DBD::File when users set individual file name for tables
506    via f_meta compatibility interface - reported by H.Merijn Brand while
507    working on RT#61168 (Jens Rehsack)
508
509  Changed 50dbm_simple to simplify and fix problems (Martin J. Evans)
510  Changed 50dbm_simple to skip aggregation tests when not using
511    SQL::Statement (Jens Rehsack)
512  Minor speed improvements in DBD::File (Jens Rehsack)
513
514  Added $h->{AutoInactiveDestroy} as simpler safer form of
515    $h->{InactiveDestroy} (David E. Wheeler)
516  Added ability for parallel testing "prove -j4 ..." (Jens Rehsack)
517  Added tests for delete in DBM (H.Merijn Brand)
518  Added test for absolute filename as table to 51dbm_file (Jens Rehsack)
519  Added two initialization phases to DBI::DBD::SqlEngine (Jens Rehsack)
520  Added improved developers documentation for DBI::DBD::SqlEngine
521    (Jens Rehsack)
522  Added guides how to write DBI drivers using DBI::DBD::SqlEngine
523    or DBD::File (Jens Rehsack)
524  Added register_compat_map() and table_meta_attr_changed() to
525    DBD::File::Table to support clean fix of RT#61168 (Jens Rehsack)
526
527=head2 Changes in DBI 1.613 (svn r14271) 22nd July 2010
528
529  Fixed Win32 prerequisite module from PathTools to File::Spec.
530
531  Changed attribute headings and fixed references in DBI pod (Martin J. Evans)
532  Corrected typos in DBI::FAQ and DBI::ProxyServer (Ansgar Burchardt)
533
534=head2 Changes in DBI 1.612 (svn r14254) 16th July 2010
535
536NOTE: This is a minor release for the DBI core but a major release for
537DBD::File and drivers that depend on it, like DBD::DBM and DBD::CSV.
538
539This is also the first release where the bulk of the development work
540has been done by other people. I'd like to thank (in no particular order)
541Jens Rehsack, Martin J. Evans, and H.Merijn Brand for all their contributions.
542
543  Fixed DBD::File's {ChopBlank} handling (it stripped \s instead of space
544    only as documented in DBI) (H.Merijn Brand)
545  Fixed DBD::DBM breakage with SQL::Statement (Jens Rehsack, fixes RT#56561)
546  Fixed DBD::File file handle leak (Jens Rehsack)
547  Fixed problems in 50dbm.t when running tests with multiple
548    dbms (Martin J. Evans)
549  Fixed DBD::DBM bugs found during tests (Jens Rehsack)
550  Fixed DBD::File doesn't find files without extensions under some
551    circumstances (Jens Rehsack, H.Merijn Brand, fixes RT#59038)
552
553  Changed Makefile.PL to modernize with CONFLICTS, recommended dependencies
554    and resources (Jens Rehsack)
555  Changed DBI::ProfileDumper to rename any existing profile file by
556    appending .prev, instead of overwriting it.
557  Changed DBI::ProfileDumper::Apache to work in more configurations
558    including vhosts using PerlOptions +Parent.
559  Add driver_prefix method to DBI (Jens Rehsack)
560
561  Added more tests to 50dbm_simple.t to prove optimizations in
562    DBI::SQL::Nano and SQL::Statement (Jens Rehsack)
563  Updated tests to cover optional installed SQL::Statement (Jens Rehsack)
564  Synchronize API between SQL::Statement and DBI::SQL::Nano (Jens Rehsack)
565  Merged some optimizations from SQL::Statement into DBI::SQL::Nano
566    (Jens Rehsack)
567  Added basic test for DBD::File (H.Merijn Brand, Jens Rehsack)
568  Extract dealing with Perl SQL engines from DBD::File into
569    DBI::DBD::SqlEngine for better subclassing of 3rd party non-db DBDs
570    (Jens Rehsack)
571
572  Updated and clarified documentation for finish method (Tim Bunce).
573  Changes to DBD::File for better English and hopefully better
574    explanation (Martin J. Evans)
575  Update documentation of DBD::DBM to cover current implementation,
576    tried to explain some things better and changes most examples to
577    preferred style of Merijn and myself (Jens Rehsack)
578  Added developer documentation (including a roadmap of future plans)
579    for DBD::File
580
581=head2 Changes in DBI 1.611 (svn r13935) 29th April 2010
582
583  NOTE: minimum perl version is now 5.8.1 (as announced in DBI 1.607)
584
585  Fixed selectcol_arrayref MaxRows attribute to count rows not values
586    thanks to Vernon Lyon.
587  Fixed DBI->trace(0, *STDERR); (H.Merijn Brand)
588    which tried to open a file named "*main::STDERR" in perl-5.10.x
589  Fixes in DBD::DBM for use under threads (Jens Rehsack)
590
591  Changed "Issuing rollback() due to DESTROY without explicit disconnect"
592    warning to not be issued if ReadOnly set for that dbh.
593
594  Added f_lock and f_encoding support to DBD::File (H.Merijn Brand)
595  Added ChildCallbacks => { ... } to Callbacks as a way to
596    specify Callbacks for child handles.
597    With tests added by David E. Wheeler.
598  Added DBI::sql_type_cast($value, $type, $flags) to cast a string value
599    to an SQL type. e.g. SQL_INTEGER effectively does $value += 0;
600    Has other options plus an internal interface for drivers.
601
602  Documentation changes:
603  Small fixes in the documentation of DBD::DBM (H.Merijn Brand)
604  Documented specification of type casting behaviour for bind_col()
605    based on DBI::sql_type_cast() and two new bind_col attributes
606    StrictlyTyped and DiscardString. Thanks to Martin Evans.
607  Document fetchrow_hashref() behaviour for functions,
608    aliases and duplicate names (H.Merijn Brand)
609  Updated DBI::Profile and DBD::File docs to fix pod nits
610    thanks to Frank Wiegand.
611  Corrected typos in Gopher documentation reported by Jan Krynicky.
612  Documented the Callbacks attribute thanks to David E. Wheeler.
613  Corrected the Timeout examples as per rt 50621 (Martin J. Evans).
614  Removed some internal broken links in the pod (Martin J. Evans)
615  Added Note to column_info for drivers which do not
616    support it (Martin J. Evans)
617  Updated dbipport.h to Devel::PPPort 3.19 (H.Merijn Brand)
618
619=head2 Changes in DBI 1.609 (svn r12816) 8th June 2009
620
621  Fixes to DBD::File (H.Merijn Brand)
622    added f_schema attribute
623    table names case sensitive when quoted, insensitive when unquoted
624    workaround a bug in SQL::Statement (temporary fix) related
625      to the "You passed x parameters where y required" error
626
627  Added ImplementorClass and Name info to the "Issuing rollback() due to
628    DESTROY without explicit disconnect" warning to identify the handle.
629    Applies to compiled drivers when they are recompiled.
630  Added DBI->visit_handles($coderef) method.
631  Added $h->visit_child_handles($coderef) method.
632  Added docs for column_info()'s COLUMN_DEF value.
633  Clarified docs on stickyness of data type via bind_param().
634  Clarified docs on stickyness of data type via bind_col().
635
636=head2 Changes in DBI 1.608 (svn r12742) 5th May 2009
637
638  Fixes to DBD::File (H.Merijn Brand)
639    bind_param () now honors the attribute argument
640    added f_ext attribute
641    File::Spec is always required. (CORE since 5.00405)
642    Fail and set errstr on parameter count mismatch in execute ()
643  Fixed two small memory leaks when running in mod_perl
644    one in DBI->connect and one in DBI::Gofer::Execute.
645    Both due to "local $ENV{...};" leaking memory.
646  Fixed DBD_ATTRIB_DELETE macro for driver authors
647    and updated DBI::DBD docs thanks to Martin J. Evans.
648  Fixed 64bit issues in trace messages thanks to Charles Jardine.
649  Fixed FETCH_many() method to work with drivers that incorrectly return
650    an empty list from $h->FETCH. Affected gofer.
651
652  Added 'sqlite_' as registered prefix for DBD::SQLite.
653  Corrected many typos in DBI docs thanks to Martin J. Evans.
654  Improved DBI::DBD docs thanks to H.Merijn Brand.
655
656=head2 Changes in DBI 1.607 (svn r11571) 22nd July 2008
657
658  NOTE: Perl 5.8.1 is now the minimum supported version.
659  If you need support for earlier versions send me a patch.
660
661  Fixed missing import of carp in DBI::Gofer::Execute.
662
663  Added note to docs about effect of execute(@empty_array).
664  Clarified docs for ReadOnly thanks to Martin Evans.
665
666=head2 Changes in DBI 1.605 (svn r11434) 16th June 2008
667
668  Fixed broken DBIS macro with threads on big-endian machines
669    with 64bit ints but 32bit pointers. Ticket #32309.
670  Fixed the selectall_arrayref, selectrow_arrayref, and selectrow_array
671    methods that get embedded into compiled drivers to use the
672    inner sth handle when passed a $sth instead of an sql string.
673    Drivers will need to be recompiled to pick up this change.
674  Fixed leak in neat() for some kinds of values thanks to Rudolf Lippan.
675  Fixed DBI::PurePerl neat() to behave more like XS neat().
676
677  Increased default $DBI::neat_maxlen from 400 to 1000.
678  Increased timeout on tests to accommodate very slow systems.
679  Changed behaviour of trace levels 1..4 to show less information
680    at lower levels.
681  Changed the format of the key used for $h->{CachedKids}
682    (which is undocumented so you shouldn't depend on it anyway)
683  Changed gofer error handling to avoid duplicate error text in errstr.
684  Clarified docs re ":N" style placeholders.
685  Improved gofer retry-on-error logic and refactored to aid subclassing.
686  Improved gofer trace output in assorted ways.
687
688  Removed the beeps "\a" from Makefile.PL warnings.
689  Removed check for PlRPC-modules from Makefile.PL
690
691  Added sorting of ParamValues reported by ShowErrorStatement
692    thanks to to Rudolf Lippan.
693  Added cache miss trace message to DBD::Gofer transport class.
694  Added $drh->dbixs_revision method.
695  Added explicit LICENSE specification (perl) to META.yaml
696
697=head2 Changes in DBI 1.604 (svn rev 10994) 24th March 2008
698
699  Fixed fetchall_arrayref with $max_rows argument broken in 1.603,
700    thanks to Greg Sabino Mullane.
701  Fixed a few harmless compiler warnings on cygwin.
702
703=head2 Changes in DBI 1.603
704
705  Fixed pure-perl fetchall_arrayref with $max_rows argument
706    to not error when fetching after all rows already fetched.
707    (Was fixed for compiled drivers back in DBI 1.31.)
708    Thanks to Mark Overmeer.
709  Fixed C sprintf formats and casts, fixing compiler warnings.
710
711  Changed dbi_profile() to accept a hash of profiles and apply to all.
712  Changed gofer stream transport to improve error reporting.
713  Changed gofer test timeout to avoid spurious failures on slow systems.
714
715  Added options to t/85gofer.t so it's more useful for manual testing.
716
717=head2 Changes in DBI 1.602 (svn rev 10706)  8th February 2008
718
719  Fixed potential coredump if stack reallocated while calling back
720    into perl from XS code. Thanks to John Gardiner Myers.
721  Fixed DBI::Util::CacheMemory->new to not clear the cache.
722  Fixed avg in DBI::Profile as_text() thanks to Abe Ingersoll.
723  Fixed DBD::DBM bug in push_names thanks to J M Davitt.
724  Fixed take_imp_data for some platforms thanks to Jeffrey Klein.
725  Fixed docs tie'ing CacheKids (ie LRU cache) thanks to Peter John Edwards.
726
727  Expanded DBI::DBD docs for driver authors thanks to Martin Evans.
728  Enhanced t/80proxy.t test script.
729  Enhanced t/85gofer.t test script thanks to Stig.
730  Enhanced t/10examp.t test script thanks to David Cantrell.
731  Documented $DBI::stderr as the default value of err for internal errors.
732
733  Gofer changes:
734    track_recent now also keeps track of N most recent errors.
735    The connect method is now also counted in stats.
736
737=head2 Changes in DBI 1.601 (svn rev 10103),  21st October 2007
738
739  Fixed t/05thrclone.t to work with Test::More >= 0.71
740    thanks to Jerry D. Hedden and Michael G Schwern.
741  Fixed DBI for VMS thanks to Peter (Stig) Edwards.
742
743  Added client-side caching to DBD::Gofer. Can use any cache with
744    get($k)/set($k,$v) methods, including all the Cache and Cache::Cache
745    distribution modules plus Cache::Memcached, Cache::FastMmap etc.
746    Works for all transports. Overridable per handle.
747
748  Added DBI::Util::CacheMemory for use with DBD::Gofer caching.
749    It's a very fast and small strict subset of Cache::Memory.
750
751=head2 Changes in DBI 1.59 (svn rev 9874),  23rd August 2007
752
753  Fixed DBI::ProfileData to unescape headers lines read from data file.
754  Fixed DBI::ProfileData to not clobber $_, thanks to Alexey Tourbin.
755  Fixed DBI::SQL::Nano to not clobber $_, thanks to Alexey Tourbin.
756  Fixed DBI::PurePerl to return undef for ChildHandles if weaken not available.
757  Fixed DBD::Proxy disconnect error thanks to Philip Dye.
758  Fixed DBD::Gofer::Transport::Base bug (typo) in timeout code.
759  Fixed DBD::Proxy rows method thanks to Philip Dye.
760  Fixed dbiprof compile errors, thanks to Alexey Tourbin.
761  Fixed t/03handle.t to skip some tests if ChildHandles not available.
762
763  Added check_response_sub to DBI::Gofer::Execute
764
765=head2 Changes in DBI 1.58 (svn rev 9678),  25th June 2007
766
767  Fixed code triggering fatal error in bleadperl, thanks to Steve Hay.
768  Fixed compiler warning thanks to Jerry D. Hedden.
769  Fixed t/40profile.t to use int(dbi_time()) for systems like Cygwin where
770    time() seems to be rounded not truncated from the high resolution time.
771  Removed dump_results() test from t/80proxy.t.
772
773=head2 Changes in DBI 1.57 (svn rev 9639),  13th June 2007
774
775  Note: this release includes a change to the DBI::hash() function which will
776  now produce different values than before *if* your perl was built with 64-bit
777  'int' type (i.e. "perl -V:intsize" says intsize='8').  It's relatively rare
778  for perl to be configured that way, even on 64-bit systems.
779
780  Fixed XS versions of select*_*() methods to call execute()
781    fetch() etc., with inner handle instead of outer.
782  Fixed execute_for_fetch() to not cache errstr values
783    thanks to Bart Degryse.
784  Fixed unused var compiler warning thanks to JDHEDDEN.
785  Fixed t/86gofer_fail tests to be less likely to fail falsely.
786
787  Changed DBI::hash to return 'I32' type instead of 'int' so results are
788    portable/consistent regardless of size of the int type.
789  Corrected timeout example in docs thanks to Egmont Koblinger.
790  Changed t/01basic.t to warn instead of failing when it detects
791    a problem with Math::BigInt (some recent versions had problems).
792
793  Added support for !Time and !Time~N to DBI::Profile Path. See docs.
794  Added extra trace info to connect_cached thanks to Walery Studennikov.
795  Added non-random (deterministic) mode to DBI_GOFER_RANDOM mechanism.
796  Added DBIXS_REVISION macro that drivers can use.
797  Added more docs for private_attribute_info() method.
798
799  DBI::Profile changes:
800    dbi_profile() now returns ref to relevant leaf node.
801    Don't profile DESTROY during global destruction.
802    Added as_node_path_list() and as_text() methods.
803  DBI::ProfileDumper changes:
804    Don't write file if there's no profile data.
805    Uses full natural precision when saving data (was using %.6f)
806    Optimized flush_to_disk().
807    Locks the data file while writing.
808    Enabled filename to be a code ref for dynamic names.
809  DBI::ProfileDumper::Apache changes:
810    Added Quiet=>1 to avoid write to STDERR in flush_to_disk().
811    Added Dir=>... to specify a writable destination directory.
812    Enabled DBI_PROFILE_APACHE_LOG_DIR for mod_perl 1 as well as 2.
813    Added parent pid to default data file name.
814  DBI::ProfileData changes:
815    Added DeleteFiles option to rename & delete files once read.
816    Locks the data files while reading.
817    Added ability to sort by Path elements.
818  dbiprof changes:
819    Added --dumpnodes and --delete options.
820  Added/updated docs for both DBI::ProfileDumper && ::Apache.
821
822=head2 Changes in DBI 1.56 (svn rev 9660),  18th June 2007
823
824  Fixed printf arg warnings thanks to JDHEDDEN.
825  Fixed returning driver-private sth attributes via gofer.
826
827  Changed pod docs docs to use =head3 instead of =item
828    so now in html you get links to individual methods etc.
829  Changed default gofer retry_limit from 2 to 0.
830  Changed tests to workaround Math::BigInt broken versions.
831  Changed dbi_profile_merge() to dbi_profile_merge_nodes()
832    old name still works as an alias for the new one.
833  Removed old DBI internal sanity check that's no longer valid
834    causing "panic: DESTROY (dbih_clearcom)" when tracing enabled
835
836  Added DBI_GOFER_RANDOM env var that can be use to trigger random
837    failures and delays when executing gofer requests. Designed to help
838    test automatic retry on failures and timeout handling.
839  Added lots more docs to all the DBD::Gofer and DBI::Gofer classes.
840
841=head2 Changes in DBI 1.55 (svn rev 9504),  4th May 2007
842
843  Fixed set_err() so HandleSetErr hook is executed reliably, if set.
844  Fixed accuracy of profiling when perl configured to use long doubles.
845  Fixed 42prof_data.t on fast systems with poor timers thanks to Malcolm Nooning.
846  Fixed potential corruption in selectall_arrayref and selectrow_arrayref
847    for compiled drivers, thanks to Rob Davies.
848    Rebuild your compiled drivers after installing DBI.
849
850  Changed some handle creation code from perl to C code,
851    to reduce handle creation cost by ~20%.
852  Changed internal implementation of the CachedKids attribute
853    so it's a normal handle attribute (and initially undef).
854  Changed connect_cached and prepare_cached to avoid a FETCH method call,
855    and thereby reduced cost by ~5% and ~30% respectively.
856  Changed _set_fbav to not croak when given a wrongly sized array,
857    it now warns and adjusts the row buffer to match.
858  Changed some internals to improve performance with threaded perls.
859  Changed DBD::NullP to be slightly more useful for testing.
860  Changed File::Spec prerequisite to not require a minimum version.
861  Changed tests to work with other DBMs thanks to ZMAN.
862  Changed ex/perl_dbi_nulls_test.pl to be more descriptive.
863
864  Added more functionality to the (undocumented) Callback mechanism.
865    Callbacks can now elect to provide a value to be returned, in which case
866    the method won't be called. A callback for "*" is applied to all methods
867    that don't have their own callback.
868  Added $h->{ReadOnly} attribute.
869  Added support for DBI Profile Path to contain refs to scalars
870    which will be de-ref'd for each profile sample.
871  Added dbilogstrip utility to edit DBI logs for diff'ing (gets installed)
872  Added details for SQLite 3.3 to NULL handling docs thanks to Alex Teslik.
873  Added take_imp_data() to DBI::PurePerl.
874
875  Gofer related changes:
876    Fixed gofer pipeone & stream transports to avoid risk of hanging.
877    Improved error handling and tracing significantly.
878    Added way to generate random 1-in-N failures for methods.
879    Added automatic retry-on-error mechanism to gofer transport base class.
880    Added tests to show automatic retry mechanism works a treat!
881    Added go_retry_hook callback hook so apps can fine-tune retry behaviour.
882    Added header to request and response packets for sanity checking
883      and to enable version skew between client and server.
884    Added forced_single_resultset, max_cached_sth_per_dbh and max_cached_dbh_per_drh
885      to gofer executor config.
886    Driver-private methods installed with install_method are now proxied.
887    No longer does a round-trip to the server for methods it knows
888      have not been overridden by the remote driver.
889    Most significant aspects of gofer behaviour are controlled by policy mechanism.
890    Added policy-controlled caching of results for some methods, such as schema metadata.
891    The connect_cached and prepare_cached methods cache on client and server.
892    The bind_param_array and execute_array methods are now supported.
893    Worked around a DBD::Sybase bind_param bug (which is fixed in DBD::Sybase 1.07)
894    Added goferperf.pl utility (doesn't get installed).
895    Many other assorted Gofer related bug fixes, enhancements and docs.
896    The http and mod_perl transports have been remove to their own distribution.
897    Client and server will need upgrading together for this release.
898
899=head2 Changes in DBI 1.54 (svn rev 9157),  23rd February 2007
900
901  NOTE: This release includes the 'next big thing': DBD::Gofer.
902  Take a look!
903
904  WARNING: This version has some subtle changes in DBI internals.
905  It's possible, though doubtful, that some may affect your code.
906  I recommend some extra testing before using this release.
907  Or perhaps I'm just being over cautious...
908
909  Fixed type_info when called for multiple dbh thanks to Cosimo Streppone.
910  Fixed compile warnings in bleadperl on freebsd-6.1-release
911    and solaris 10g thanks to Philip M. Gollucci.
912  Fixed to compile for perl built with -DNO_MATHOMS thanks to Jerry D. Hedden.
913  Fixed to work for bleadperl (r29544) thanks to Nicholas Clark.
914    Users of Perl >= 5.9.5 will require DBI >= 1.54.
915  Fixed rare error when profiling access to $DBI::err etc tied variables.
916  Fixed DBI::ProfileDumper to not be affected by changes to $/ and $,
917    thanks to Michael Schwern.
918
919  Changed t/40profile.t to skip tests for perl < 5.8.0.
920  Changed setting trace file to no longer write "Trace file set" to new file.
921  Changed 'handle cleared whilst still active' warning for dbh
922    to only be given for dbh that have active sth or are not AutoCommit.
923  Changed take_imp_data to call finish on all Active child sth.
924  Changed DBI::PurePerl trace() method to be more consistent.
925  Changed set_err method to effectively not append to errstr if the new errstr
926    is the same as the current one.
927  Changed handle factory methods, like connect, prepare, and table_info,
928    to copy any error/warn/info state of the handle being returned
929    up into the handle the method was called on.
930  Changed row buffer handling to not alter NUM_OF_FIELDS if it's
931    inconsistent with number of elements in row buffer array.
932  Updated DBI::DBD docs re handling multiple result sets.
933  Updated DBI::DBD docs for driver authors thanks to Ammon Riley
934    and Dean Arnold.
935  Updated column_info docs to note that if a table doesn't exist
936    you get an sth for an empty result set and not an error.
937
938  Added new DBD::Gofer 'stateless proxy' driver and framework,
939    and the DBI test suite is now also executed via DBD::Gofer,
940    and DBD::Gofer+DBI::PurePerl, in addition to DBI::PurePerl.
941  Added ability for trace() to support filehandle argument,
942    including tracing into a string, thanks to Dean Arnold.
943  Added ability for drivers to implement func() method
944    so proxy drivers can proxy the func method itself.
945  Added SQL_BIGINT type code (resolved to the ODBC/JDBC value (-5))
946  Added $h->private_attribute_info method.
947
948=head2 Changes in DBI 1.53 (svn rev 7995),   31st October 2006
949
950  Fixed checks for weaken to work with early 5.8.x versions
951  Fixed DBD::Proxy handling of some methods, including commit and rollback.
952  Fixed t/40profile.t to be more insensitive to long double precision.
953  Fixed t/40profile.t to be insensitive to small negative shifts in time
954    thanks to Jamie McCarthy.
955  Fixed t/40profile.t to skip tests for perl < 5.8.0.
956  Fixed to work with current 'bleadperl' (~5.9.5) thanks to Steve Peters.
957    Users of Perl >= 5.9.5 will require DBI >= 1.53.
958  Fixed to be more robust against drivers not handling multiple result
959    sets properly, thanks to Gisle Aas.
960
961  Added array context support to execute_array and execute_for_fetch
962    methods which returns executed tuples and rows affected.
963  Added Tie::Cache::LRU example to docs thanks to Brandon Black.
964
965=head2 Changes in DBI 1.52 (svn rev 6840),   30th July 2006
966
967  Fixed memory leak (per handle) thanks to Nicholas Clark and Ephraim Dan.
968  Fixed memory leak (16 bytes per sth) thanks to Doru Theodor Petrescu.
969  Fixed execute_for_fetch/execute_array to RaiseError thanks to Martin J. Evans.
970  Fixed for perl 5.9.4. Users of Perl >= 5.9.4 will require DBI >= 1.52.
971
972  Updated DBD::File to 0.35 to match the latest release on CPAN.
973
974  Added $dbh->statistics_info specification thanks to Brandon Black.
975
976  Many changes and additions to profiling:
977    Profile Path can now uses sane strings instead of obscure numbers,
978    can refer to attributes, assorted magical values, and even code refs!
979    Parsing of non-numeric DBI_PROFILE env var values has changed.
980    Changed DBI::Profile docs extensively - many new features.
981    See DBI::Profile docs for more information.
982
983=head2 Changes in DBI 1.51 (svn rev 6475),   6th June 2006
984
985  Fixed $dbh->clone method 'signature' thanks to Jeffrey Klein.
986  Fixed default ping() method to return false if !$dbh->{Active}.
987  Fixed t/40profile.t to be insensitive to long double precision.
988  Fixed for perl 5.8.0's more limited weaken() function.
989  Fixed DBD::Proxy to not alter $@ in disconnect or AUTOLOADd methods.
990  Fixed bind_columns() to use return set_err(...) instead of die()
991    to report incorrect number of parameters, thanks to Ben Thul.
992  Fixed bind_col() to ignore undef as bind location, thanks to David Wheeler.
993  Fixed for perl 5.9.x for non-threaded builds thanks to Nicholas Clark.
994    Users of Perl >= 5.9.x will require DBI >= 1.51.
995  Fixed fetching of rows as hash refs to preserve utf8 on field names
996    from $sth->{NAME} thanks to Alexey Gaidukov.
997  Fixed build on Win32 (dbd_postamble) thanks to David Golden.
998
999  Improved performance for thread-enabled perls thanks to Gisle Aas.
1000  Drivers can now use PERL_NO_GET_CONTEXT thanks to Gisle Aas.
1001    Driver authors please read the notes in the DBI::DBD docs.
1002  Changed DBI::Profile format to always include a percentage,
1003    if not exiting then uses time between the first and last DBI call.
1004  Changed DBI::ProfileData to be more forgiving of systems with
1005    unstable clocks (where time may go backwards occasionally).
1006  Clarified the 'Subclassing the DBI' docs.
1007  Assorted minor changes to docs from comments on annocpan.org.
1008  Changed Makefile.PL to avoid incompatible options for old gcc.
1009
1010  Added 'fetch array of hash refs' example to selectall_arrayref
1011    docs thanks to Tom Schindl.
1012  Added docs for $sth->{ParamArrays} thanks to Martin J. Evans.
1013  Added reference to $DBI::neat_maxlen in TRACING section of docs.
1014  Added ability for DBI::Profile Path to include attributes
1015    and a summary of where the code was called from.
1016
1017=head2 Changes in DBI 1.50 (svn rev 2307),   13 December 2005
1018
1019  Fixed Makefile.PL options for gcc bug introduced in 1.49.
1020  Fixed handle magic order to keep DBD::Oracle happy.
1021  Fixed selectrow_array to return empty list on error.
1022
1023  Changed dbi_profile_merge() to be able to recurse and merge
1024    sub-trees of profile data.
1025
1026  Added documentation for dbi_profile_merge(), including how to
1027    measure the time spent inside the DBI for an http request.
1028
1029=head2 Changes in DBI 1.49 (svn rev 2287),   29th November 2005
1030
1031  Fixed assorted attribute handling bugs in DBD::Proxy.
1032  Fixed croak() in DBD::NullP thanks to Sergey Skvortsov.
1033  Fixed handling of take_imp_data() and dbi_imp_data attribute.
1034  Fixed bugs in DBD::DBM thanks to Jeff Zucker.
1035  Fixed bug in DBI::ProfileDumper thanks to Sam Tregar.
1036  Fixed ping in DBD::Proxy thanks to George Campbell.
1037  Fixed dangling ref in $sth after parent $dbh destroyed
1038    with thanks to il@rol.ru for the bug report #13151
1039  Fixed prerequisites to include Storable thanks to Michael Schwern.
1040  Fixed take_imp_data to be more practical.
1041
1042  Change to require perl 5.6.1 (as advertised in 2003) not 5.6.0.
1043  Changed internals to be more strictly coded thanks to Andy Lester.
1044  Changed warning about multiple copies of Driver.xst found in @INC
1045    to ignore duplicated directories thanks to Ed Avis.
1046  Changed Driver.xst to enable drivers to define an dbd_st_prepare_sv
1047    function where the statement parameter is an SV. That enables
1048    compiled drivers to support SQL strings that are UTF-8.
1049  Changed "use DBI" to only set $DBI::connect_via if not already set.
1050  Changed docs to clarify pre-method clearing of err values.
1051
1052  Added ability for DBI::ProfileData to edit profile path on loading.
1053    This enables aggregation of different SQL statements into the same
1054    profile node - very handy when not using placeholders or when working
1055    multiple separate tables for the same thing (ie logtable_2005_11_28)
1056  Added $sth->{ParamTypes} specification thanks to Dean Arnold.
1057  Added $h->{Callbacks} attribute to enable code hooks to be invoked
1058    when certain methods are called. For example:
1059    $dbh->{Callbacks}->{prepare} = sub { ... };
1060    With thanks to David Wheeler for the kick start.
1061  Added $h->{ChildHandles} (using weakrefs) thanks to Sam Tregar
1062    I've recoded it in C so there's no significant performance impact.
1063  Added $h->{Type} docs (returns 'dr', 'db', or 'st')
1064  Adding trace message in DESTROY if InactiveDestroy enabled.
1065  Added %drhs = DBI->installed_drivers();
1066
1067  Ported DBI::ProfileDumper::Apache to mod_perl2 RC5+
1068    thanks to Philip M. Golluci
1069
1070=head2 Changes in DBI 1.48 (svn rev 928),    14th March 2005
1071
1072  Fixed DBI::DBD::Metadata generation of type_info_all thanks to Steffen Goeldner
1073    (driver authors who have used it should rerun it).
1074
1075  Updated docs for NULL Value placeholders thanks to Brian Campbell.
1076
1077  Added multi-keyfield nested hash fetching to fetchall_hashref()
1078    thanks to Zhuang (John) Li for polishing up my draft.
1079  Added registered driver prefixes: amzn_ for DBD::Amazon and yaswi_ for DBD::Yaswi.
1080
1081
1082=head2 Changes in DBI 1.47 (svn rev 854),    2nd February 2005
1083
1084  Fixed DBI::ProxyServer to not create pid files by default.
1085    References: Ubuntu Security Notice USN-70-1, CAN-2005-0077
1086    Thanks to Javier Fernández-Sanguino Peña from the
1087    Debian Security Audit Project, and Jonathan Leffler.
1088  Fixed some tests to work with older Test::More versions.
1089  Fixed setting $DBI::err/errstr in DBI::PurePerl.
1090  Fixed potential undef warning from connect_cached().
1091  Fixed $DBI::lasth handling for DESTROY so lasth points to
1092    parent even if DESTROY called other methods.
1093  Fixed DBD::Proxy method calls to not alter $@.
1094  Fixed DBD::File problem with encoding pragma thanks to Erik Rijkers.
1095
1096  Changed error handling so undef errstr doesn't cause warning.
1097  Changed DBI::DBD docs to use =head3/=head4 pod thanks to
1098    Jonathan Leffler. This may generate warnings for perl 5.6.
1099  Changed DBI::PurePerl to set autoflush on trace filehandle.
1100  Changed DBD::Proxy to treat Username as a local attribute
1101    so recent DBI version can be used with old DBI::ProxyServer.
1102  Changed driver handle caching in DBD::File.
1103  Added $GetInfoType{SQL_DATABASE_NAME} thanks to Steffen Goeldner.
1104
1105  Updated docs to recommend some common DSN string attributes.
1106  Updated connect_cached() docs with issues and suggestions.
1107  Updated docs for NULL Value placeholders thanks to Brian Campbell.
1108  Updated docs for primary_key_info and primary_keys.
1109  Updated docs to clarify that the default fetchrow_hashref behaviour,
1110    of returning a ref to a new hash for each row, will not change.
1111  Updated err/errstr/state docs for DBD authors thanks to Steffen Goeldner.
1112  Updated handle/attribute docs for DBD authors thanks to Steffen Goeldner.
1113  Corrected and updated LongReadLen docs thanks to Bart Lateur.
1114  Added DBD::JDBC as a registered driver.
1115
1116=head2 Changes in DBI 1.46 (svn rev 584),    16th November 2004
1117
1118  Fixed parsing bugs in DBI::SQL::Nano thanks to Jeff Zucker.
1119  Fixed a couple of bad links in docs thanks to Graham Barr.
1120  Fixed test.pl Win32 undef warning thanks to H.Merijn Brand & David Repko.
1121  Fixed minor issues in DBI::DBD::Metadata thanks to Steffen Goeldner.
1122  Fixed DBI::PurePerl neat() to use double quotes for utf8.
1123
1124  Changed execute_array() definition, and default implementation,
1125    to not consider scalar values for execute tuple count. See docs.
1126  Changed DBD::File to enable ShowErrorStatement by default,
1127    which affects DBD::File subclasses such as DBD::CSV and DBD::DBM.
1128  Changed use DBI qw(:utils) tag to include $neat_maxlen.
1129  Updated Roadmap and ToDo.
1130
1131  Added data_string_diff() data_string_desc() and data_diff()
1132    utility functions to help diagnose Unicode issues.
1133    All can be imported via the use DBI qw(:utils) tag.
1134
1135=head2 Changes in DBI 1.45 (svn rev 480),    6th October 2004
1136
1137  Fixed DBI::DBD code for drivers broken in 1.44.
1138  Fixed "Free to wrong pool"/"Attempt to free unreferenced scalar" in FETCH.
1139
1140=head2 Changes in DBI 1.44 (svn rev 478),    5th October 2004
1141
1142  Fixed build issues on VMS thanks to Jakob Snoer.
1143  Fixed DBD::File finish() method to return 1 thanks to Jan Dubois.
1144  Fixed rare core dump during global destruction thanks to Mark Jason Dominus.
1145  Fixed risk of utf8 flag persisting from one row to the next.
1146
1147  Changed bind_param_array() so it doesn't require all bind arrays
1148    to have the same number of elements.
1149  Changed bind_param_array() to error if placeholder number <= 0.
1150  Changed execute_array() definition, and default implementation,
1151    to effectively NULL-pad shorter bind arrays.
1152  Changed execute_array() to return "0E0" for 0 as per the docs.
1153  Changed execute_for_fetch() definition, and default implementation,
1154    to return "0E0" for 0 like execute() and execute_array().
1155  Changed Test::More prerequisite to Test::Simple (which is also the name
1156    of the distribution both are packaged in) to work around ppm behaviour.
1157
1158  Corrected docs to say that get/set of unknown attribute generates
1159    a warning and is no longer fatal. Thanks to Vadim.
1160  Corrected fetchall_arrayref() docs example thanks to Drew Broadley.
1161
1162  Added $h1->swap_inner_handle($h2) sponsored by BizRate.com
1163
1164
1165=head2 Changes in DBI 1.43 (svn rev 377),    2nd July 2004
1166
1167  Fixed connect() and connect_cached() RaiseError/PrintError
1168    which would sometimes show "(no error string)" as the error.
1169  Fixed compiler warning thanks to Paul Marquess.
1170  Fixed "trace level set to" trace message thanks to H.Merijn Brand.
1171  Fixed DBD::DBM $dbh->{dbm_tables}->{...} to be keyed by the
1172    table name not the file name thanks to Jeff Zucker.
1173  Fixed last_insert_id(...) thanks to Rudy Lippan.
1174  Fixed propagation of scalar/list context into proxied methods.
1175  Fixed DBI::Profile::DESTROY to not alter $@.
1176  Fixed DBI::ProfileDumper new() docs thanks to Michael Schwern.
1177  Fixed _load_class to propagate $@ thanks to Drew Taylor.
1178  Fixed compile warnings on Win32 thanks to Robert Baron.
1179  Fixed problem building with recent versions of MakeMaker.
1180  Fixed DBD::Sponge not to generate warning with threads.
1181  Fixed DBI_AUTOPROXY to work more than once thanks to Steven Hirsch.
1182
1183  Changed TraceLevel 1 to not show recursive/nested calls.
1184  Changed getting or setting an invalid attribute to no longer be
1185    a fatal error but generate a warning instead.
1186  Changed selectall_arrayref() to call finish() if
1187    $attr->{MaxRows} is defined.
1188  Changed all tests to use Test::More and enhanced the tests thanks
1189    to Stevan Little and Andy Lester. See http://qa.perl.org/phalanx/
1190  Changed Test::More minimum prerequisite version to 0.40 (2001).
1191  Changed DBI::Profile header to include the date and time.
1192
1193  Added DBI->parse_dsn($dsn) method.
1194  Added warning if build directory path contains white space.
1195  Added docs for parse_trace_flags() and parse_trace_flag().
1196  Removed "may change" warnings from the docs for table_info(),
1197    primary_key_info(), and foreign_key_info() methods.
1198
1199=head2 Changes in DBI 1.42 (svn rev 222),    12th March 2004
1200
1201  Fixed $sth->{NUM_OF_FIELDS} of non-executed statement handle
1202    to be undef as per the docs (it was 0).
1203  Fixed t/41prof_dump.t to work with perl5.9.1.
1204  Fixed DBD_ATTRIB_DELETE macro thanks to Marco Paskamp.
1205  Fixed DBI::PurePerl looks_like_number() and $DBI::rows.
1206  Fixed ref($h)->can("foo") to not croak.
1207
1208  Changed attributes (NAME, TYPE etc) of non-executed statement
1209    handle to be undef instead of triggering an error.
1210  Changed ShowErrorStatement to apply to more $dbh methods.
1211  Changed DBI_TRACE env var so just does this at load time:
1212    DBI->trace(split '=', $ENV{DBI_TRACE}, 2);
1213  Improved "invalid number of parameters" error message.
1214  Added DBI::common as base class for DBI::db, DBD::st etc.
1215  Moved methods common to all handles into DBI::common.
1216
1217  Major tracing enhancement:
1218
1219  Added $h->parse_trace_flags("foo|SQL|7") to map a group of
1220    trace flags into the corresponding trace flag bits.
1221  Added automatic calling of parse_trace_flags() if
1222    setting the trace level to a non-numeric value:
1223    $h->{TraceLevel}="foo|SQL|7"; $h->trace("foo|SQL|7");
1224    DBI->connect("dbi:Driver(TraceLevel=SQL|foo):...", ...);
1225    Currently no trace flags have been defined.
1226  Added to, and reworked, the trace documentation.
1227  Added dbivport.h for driver authors to use.
1228
1229  Major driver additions that Jeff Zucker and I have been working on:
1230
1231  Added DBI::SQL::Nano a 'smaller than micro' SQL parser
1232    with an SQL::Statement compatible API. If SQL::Statement
1233    is installed then DBI::SQL::Nano becomes an empty subclass
1234    of SQL::Statement, unless the DBI_SQL_NANO env var is true.
1235  Added DBD::File, modified to use DBI::SQL::Nano.
1236  Added DBD::DBM, an SQL interface to DBM files using DBD::File.
1237
1238  Documentation changes:
1239
1240  Corrected typos in docs thanks to Steffen Goeldner.
1241  Corrected execute_for_fetch example thanks to Dean Arnold.
1242
1243=head2 Changes in DBI 1.41 (svn rev 130),    22nd February 2004
1244
1245  Fixed execute_for_array() so tuple_status parameter is optional
1246    as per docs, thanks to Ed Avis.
1247  Fixed execute_for_array() docs to say that it returns undef if
1248    any of the execute() calls fail.
1249  Fixed take_imp_data() test on m68k reported by Christian Hammers.
1250  Fixed write_typeinfo_pm inconsistencies in DBI::DBD::Metadata
1251    thanks to Andy Hassall.
1252  Fixed $h->{TraceLevel} to not return DBI->trace trace level
1253    which it used to if DBI->trace trace level was higher.
1254
1255  Changed set_err() to append to errstr, with a leading "\n" if it's
1256    not empty, so that multiple error/warning messages are recorded.
1257  Changed trace to limit elements dumped when an array reference is
1258    returned from a method to the max(40, $DBI::neat_maxlen/10)
1259    so that fetchall_arrayref(), for example, doesn't flood the trace.
1260  Changed trace level to be a four bit integer (levels 0 thru 15)
1261    and a set of topic flags (no topics have been assigned yet).
1262  Changed column_info() to check argument count.
1263  Extended bind_param() TYPE attribute specification to imply
1264    standard formating of value, eg SQL_DATE implies 'YYYY-MM-DD'.
1265
1266  Added way for drivers to indicate 'success with info' or 'warning'
1267    by setting err to "0" for warning and "" for information.
1268    Both values are false and so don't trigger RaiseError etc.
1269    Thanks to Steffen Goeldner for the original idea.
1270  Added $h->{HandleSetErr} = sub { ... } to be called at the
1271    point that an error, warn, or info state is recorded.
1272    The code can alter the err, errstr, and state values
1273    (e.g., to promote an error to a warning, or the reverse).
1274  Added $h->{PrintWarn} attribute to enable printing of warnings
1275    recorded by the driver. Defaults to same value as $^W (perl -w).
1276  Added $h->{ErrCount} attribute, incremented whenever an error is
1277    recorded by the driver via set_err().
1278  Added $h->{Executed} attribute, set if do()/execute() called.
1279  Added \%attr parameter to foreign_key_info() method.
1280  Added ref count of inner handle to "DESTROY ignored for outer" msg.
1281  Added Win32 build config checks to DBI::DBD thanks to Andy Hassall.
1282  Added bind_col to Driver.xst so drivers can define their own.
1283  Added TYPE attribute to bind_col and specified the expected
1284    driver behaviour.
1285
1286  Major update to signal handling docs thanks to Lincoln Baxter.
1287  Corrected dbiproxy usage doc thanks to Christian Hammers.
1288  Corrected type_info_all index hash docs thanks to Steffen Goeldner.
1289  Corrected type_info COLUMN_SIZE to chars not bytes thanks to Dean Arnold.
1290  Corrected get_info() docs to include details of DBI::Const::GetInfoType.
1291  Clarified that $sth->{PRECISION} is OCTET_LENGTH for char types.
1292
1293=head2 Changes in DBI 1.40,    7th January 2004
1294
1295  Fixed handling of CachedKids when DESTROYing threaded handles.
1296  Fixed sql_user_name() in DBI::DBD::Metadata (used by write_getinfo_pm)
1297    to use $dbh->{Username}. Driver authors please update your code.
1298
1299  Changed connect_cached() when running under Apache::DBI
1300    to route calls to Apache::DBI::connect().
1301
1302  Added CLONE() to DBD::Sponge and DBD::ExampleP.
1303  Added warning when starting a new thread about any loaded driver
1304    which does not have a CLONE() function.
1305  Added new prepare_cache($sql, \%attr, 3) option to manage Active handles.
1306  Added SCALE and NULLABLE support to DBD::Sponge.
1307  Added missing execute() in fetchall_hashref docs thanks to Iain Truskett.
1308  Added a CONTRIBUTING section to the docs with notes on creating patches.
1309
1310=head2 Changes in DBI 1.39,    27th November 2003
1311
1312  Fixed STORE to not clear error during nested DBI call, again/better,
1313    thanks to Tony Bowden for the report and helpful test case.
1314  Fixed DBI dispatch to not try to use AUTOLOAD for driver methods unless
1315    the method has been declared (as methods should be when using AUTOLOAD).
1316    This fixes a problem when the Attribute::Handlers module is loaded.
1317  Fixed cwd check code to use $Config{path_sep} thanks to Steve Hay.
1318  Fixed unqualified croak() calls thanks to Steffen Goeldner.
1319  Fixed DBD::ExampleP TYPE and PRECISION attributes thanks to Tom Lowery.
1320  Fixed tracing of methods that only get traced at high trace levels.
1321
1322  The level 1 trace no longer includes nested method calls so it generally
1323    just shows the methods the application explicitly calls.
1324  Added line to trace log (level>=4) when err/errstr is cleared.
1325  Updated docs for InactiveDestroy and point out where and when the
1326    trace includes the process id.
1327  Update DBI::DBD docs thanks to Steffen Goeldner.
1328  Removed docs saying that the DBI->data_sources method could be
1329    passed a $dbh. The $dbh->data_sources method should be used instead.
1330  Added link to 'DBI recipes' thanks to Giuseppe Maxia:
1331    http://gmax.oltrelinux.com/dbirecipes.html (note that this
1332    is not an endorsement that the recipies are 'optimal')
1333
1334  Note: There is a bug in perl 5.8.2 when configured with threads
1335  and debugging enabled (bug #24463) which causes a DBI test to fail.
1336
1337=head2 Changes in DBI 1.38,    21th August 2003
1338
1339  NOTE: The DBI now requires perl version 5.6.0 or later.
1340  (As per notice in DBI 1.33 released 27th February 2003)
1341
1342  Fixed spurious t/03handles failure on 64bit perls reported by H.Merijn Brand.
1343  Fixed spurious t/15array failure on some perl versions thanks to Ed Avis.
1344  Fixed build using dmake on windows thanks to Steffen Goeldner.
1345  Fixed build on using some shells thanks to Gurusamy Sarathy.
1346  Fixed ParamValues to only be appended to ShowErrorStatement if not empty.
1347  Fixed $dbh->{Statement} not being writable by drivers in some cases.
1348  Fixed occasional undef warnings on connect failures thanks to Ed Avis.
1349  Fixed small memory leak when using $sth->{NAME..._hash}.
1350  Fixed 64bit warnings thanks to Marian Jancar.
1351  Fixed DBD::Proxy::db::DESTROY to not alter $@ thanks to Keith Chapman.
1352  Fixed Makefile.PL status from WriteMakefile() thanks to Leon Brocard.
1353
1354  Changed "Can't set ...->{Foo}: unrecognised attribute" from an error to a
1355    warning when running with DBI::ProxyServer to simplify upgrades.
1356  Changed execute_array() to no longer require ArrayTupleStatus attribute.
1357  Changed DBI->available_drivers to not hide DBD::Sponge.
1358  Updated/moved placeholder docs to a better place thanks to Johan Vromans.
1359  Changed dbd_db_do4 api in Driver.xst to match dbd_st_execute (return int,
1360    not bool), relevant only to driver authors.
1361  Changed neat(), and thus trace(), so strings marked as utf8 are presented
1362    in double quotes instead of single quotes and are not sanitized.
1363
1364  Added $dbh->data_sources method.
1365  Added $dbh->last_insert_id method.
1366  Added $sth->execute_for_fetch($fetch_tuple_sub, \@tuple_status) method.
1367  Added DBI->installed_versions thanks to Jeff Zucker.
1368  Added $DBI::Profile::ON_DESTROY_DUMP variable.
1369  Added docs for DBD::Sponge thanks to Mark Stosberg.
1370
1371=head2 Changes in DBI 1.37,    15th May 2003
1372
1373  Fixed "Can't get dbh->{Statement}: unrecognised attribute" error in test
1374    caused by change to perl internals in 5.8.0
1375  Fixed to build with latest development perl (5.8.1@19525).
1376  Fixed C code to use all ANSI declarations thanks to Steven Lembark.
1377
1378=head2 Changes in DBI 1.36,    11th May 2003
1379
1380  Fixed DBI->connect to carp instead of croak on 'old-style' usage.
1381  Fixed connect(,,, { RootClass => $foo }) to not croak if module not found.
1382  Fixed code generated by DBI::DBD::Metadata thanks to DARREN@cpan.org (#2270)
1383  Fixed DBI::PurePerl to not reset $@ during method dispatch.
1384  Fixed VMS build thanks to Michael Schwern.
1385  Fixed Proxy disconnect thanks to Steven Hirsch.
1386  Fixed error in DBI::DBD docs thanks to Andy Hassall.
1387
1388  Changed t/40profile.t to not require Time::HiRes.
1389  Changed DBI::ProxyServer to load DBI only on first request, which
1390    helps threaded server mode, thanks to Bob Showalter.
1391  Changed execute_array() return value from row count to executed
1392    tuple count, and now the ArrayTupleStatus attribute is mandatory.
1393    NOTE: That is an API definition change that may affect your code.
1394  Changed CompatMode attribute to also disable attribute 'quick FETCH'.
1395  Changed attribute FETCH to be slightly faster thanks to Stas Bekman.
1396
1397  Added workaround for perl bug #17575 tied hash nested FETCH
1398    thanks to Silvio Wanka.
1399  Added Username and Password attributes to connect(..., \%attr) and so
1400    also embedded in DSN like "dbi:Driver(Username=user,Password=pass):..."
1401    Username and Password can't contain ")", ",", or "=" characters.
1402    The predence is DSN first, then \%attr, then $user & $pass parameters,
1403    and finally the DBI_USER & DBI_PASS environment variables.
1404    The Username attribute is stored in the $dbh but the Password is not.
1405  Added ProxyServer HOWTO configure restrictions docs thanks to Jochen Wiedmann.
1406  Added MaxRows attribute to selectcol_arrayref prompted by Wojciech Pietron.
1407  Added dump_handle as a method not just a DBI:: utility function.
1408  Added on-demand by-row data feed into execute_array() using code ref,
1409    or statement handle. For example, to insert from a select:
1410    $insert_sth->execute_array( { ArrayTupleFetch => $select_sth, ... } )
1411  Added warning to trace log when $h->{foo}=... is ignored due to
1412    invalid prefix (e.g., not 'private_').
1413
1414=head2 Changes in DBI 1.35,    7th March 2003
1415
1416  Fixed memory leak in fetchrow_hashref introduced in DBI 1.33.
1417  Fixed various DBD::Proxy errors introduced in DBI 1.33.
1418  Fixed to ANSI C in dbd_dr_data_sources thanks to Jonathan Leffler.
1419  Fixed $h->can($method_name) to return correct code ref.
1420  Removed DBI::Format from distribution as it's now part of the
1421    separate DBI::Shell distribution by Tom Lowery.
1422  Updated DBI::DBD docs with a note about the CLONE method.
1423  Updated DBI::DBD docs thanks to Jonathan Leffler.
1424  Updated DBI::DBD::Metadata for perl 5.5.3 thanks to Jonathan Leffler.
1425  Added note to install_method docs about setup_driver() method.
1426
1427=head2 Changes in DBI 1.34,    28th February 2003
1428
1429  Fixed DBI::DBD docs to refer to DBI::DBD::Metadata thanks to Jonathan Leffler.
1430  Fixed dbi_time() compile using BorlandC on Windows thanks to Steffen Goeldner.
1431  Fixed profile tests to do enough work to measure on Windows.
1432  Fixed disconnect_all() to not be required by drivers.
1433
1434  Added $okay = $h->can($method_name) to check if a method exists.
1435  Added DBD::*::*->install_method($method_name, \%attr) so driver private
1436    methods can be 'installed' into the DBI dispatcher and no longer
1437    need to be called using $h->func(..., $method_name).
1438
1439  Enhanced $dbh->clone() and documentation.
1440  Enhanced docs to note that dbi_time(), and thus profiling, is limited
1441    to only millisecond (seconds/1000) resolution on Windows.
1442  Removed old DBI::Shell from distribution and added Tom Lowery's improved
1443    version to the Bundle::DBI file.
1444  Updated minimum version numbers for modules in Bundle::DBI.
1445
1446=head2 Changes in DBI 1.33,    27th February 2003
1447
1448  NOTE: Future versions of the DBI *will not* support perl 5.6.0 or earlier.
1449  : Perl 5.6.1 will be the minimum supported version.
1450
1451  NOTE: The "old-style" connect: DBI->connect($database, $user, $pass, $driver);
1452  : has been deprecated for several years and will now generate a warning.
1453  : It will be removed in a later release. Please change any old connect() calls.
1454
1455  Added $dbh2 = $dbh1->clone to make a new connection to the database
1456    that is identical to the original one. clone() can be called even after
1457    the original handle has been disconnected. See the docs for more details.
1458
1459  Fixed merging of profile data to not sum DBIprof_FIRST_TIME values.
1460  Fixed unescaping of newlines in DBI::ProfileData thanks to Sam Tregar.
1461  Fixed Taint bug with fetchrow_hashref with help from Bradley Baetz.
1462  Fixed $dbh->{Active} for DBD::Proxy, reported by Bob Showalter.
1463  Fixed STORE to not clear error during nested DBI call,
1464    thanks to Tony Bowden for the report and helpful test case.
1465  Fixed DBI::PurePerl error clearing behaviour.
1466  Fixed dbi_time() and thus DBI::Profile on Windows thanks to Smejkal Petr.
1467  Fixed problem that meant ShowErrorStatement could show wrong statement,
1468   thanks to Ron Savage for the report and test case.
1469  Changed Apache::DBI hook to check for $ENV{MOD_PERL} instead of
1470    $ENV{GATEWAY_INTERFACE} thanks to Ask Bjoern Hansen.
1471  No longer tries to dup trace logfp when an interpreter is being cloned.
1472  Database handles no longer inherit shared $h->err/errstr/state storage
1473    from their drivers, so each $dbh has it's own $h->err etc. values
1474    and is no longer affected by calls made on other dbh's.
1475    Now when a dbh is destroyed it's err/errstr/state values are copied
1476    up to the driver so checking $DBI::errstr still works as expected.
1477
1478  Build / portability fixes:
1479    Fixed t/40profile.t to not use Time::HiRes.
1480    Fixed t/06attrs.t to not be locale sensitive, reported by Christian Hammers.
1481    Fixed sgi compiler warnings, reported by Paul Blake.
1482    Fixed build using make -j4, reported by Jonathan Leffler.
1483    Fixed build and tests under VMS thanks to Craig A. Berry.
1484
1485  Documentation changes:
1486    Documented $high_resolution_time = dbi_time() function.
1487    Documented that bind_col() can take an attribute hash.
1488    Clarified documentation for ParamValues attribute hash keys.
1489    Many good DBI documentation tweaks from Jonathan Leffler,
1490      including a major update to the DBI::DBD driver author guide.
1491    Clarified that execute() should itself call finish() if it's
1492      called on a statement handle that's still active.
1493    Clarified $sth->{ParamValues}. Driver authors please note.
1494    Removed "NEW" markers on some methods and attributes and
1495      added text to each giving the DBI version it was added in,
1496      if it was added after DBI 1.21 (Feb 2002).
1497
1498  Changes of note for authors of all drivers:
1499    Added SQL_DATA_TYPE, SQL_DATETIME_SUB, NUM_PREC_RADIX, and
1500      INTERVAL_PRECISION fields to docs for type_info_all. There were
1501      already in type_info(), but type_info_all() didn't specify the
1502      index values.  Please check and update your type_info_all() code.
1503    Added DBI::DBD::Metadata module that auto-generates your drivers
1504      get_info and type_info_all data and code, thanks mainly to
1505      Jonathan Leffler and Steffen Goeldner. If you've not implemented
1506      get_info and type_info_all methods and your database has an ODBC
1507      driver available then this will do all the hard work for you!
1508    Drivers should no longer pass Err, Errstr, or State to _new_drh
1509      or _new_dbh functions.
1510    Please check that you support the slightly modified behaviour of
1511      $sth->{ParamValues}, e.g., always return hash with keys if possible.
1512
1513  Changes of note for authors of compiled drivers:
1514    Added dbd_db_login6 & dbd_st_finish3 prototypes thanks to Jonathan Leffler.
1515    All dbd_*_*() functions implemented by drivers must have a
1516      corresponding #define dbd_*_* <driver_prefix>_*_* otherwise
1517      the driver may not work with a future release of the DBI.
1518
1519  Changes of note for authors of drivers which use Driver.xst:
1520    Some new method hooks have been added are are enabled by
1521      defining corresponding macros:
1522          $drh->data_sources()      - dbd_dr_data_sources
1523          $dbh->do()                - dbd_db_do4
1524    The following methods won't be compiled into the driver unless
1525      the corresponding macro has been #defined:
1526          $drh->disconnect_all()    - dbd_discon_all
1527
1528
1529=head2 Changes in DBI 1.32,    1st December 2002
1530
1531  Fixed to work with 5.005_03 thanks to Tatsuhiko Miyagawa (I've not tested it).
1532  Reenabled taint tests (accidentally left disabled) spotted by Bradley Baetz.
1533  Improved docs for FetchHashKeyName attribute thanks to Ian Barwick.
1534  Fixed core dump if fetchrow_hashref given bad argument (name of attribute
1535    with a value that wasn't an array reference), spotted by Ian Barwick.
1536  Fixed some compiler warnings thanks to David Wheeler.
1537  Updated Steven Hirsch's enhanced proxy work (seems I left out a bit).
1538  Made t/40profile.t tests more reliable, reported by Randy, who is part of
1539    the excellent CPAN testers team: http://testers.cpan.org/
1540    (Please visit, see the valuable work they do and, ideally, join in!)
1541
1542=head2 Changes in DBI 1.31,    29th November 2002
1543
1544  The fetchall_arrayref method, when called with a $maxrows parameter,
1545    no longer gives an error if called again after all rows have been
1546    fetched. This simplifies application logic when fetching in batches.
1547    Also added batch-fetch while() loop example to the docs.
1548  The proxy now supports non-lazy (synchronous) prepare, positioned
1549    updates (for selects containing 'for update'), PlRPC config set
1550    via attributes, and accurate propagation of errors, all thanks
1551    to Steven Hirsch (plus a minor fix from Sean McMurray and doc
1552    tweaks from Michael A Chase).
1553  The DBI_AUTOPROXY env var can now hold the full dsn of the proxy driver
1554    plus attributes, like "dbi:Proxy(proxy_foo=>1):host=...".
1555  Added TaintIn & TaintOut attributes to give finer control over
1556    tainting thanks to Bradley Baetz.
1557  The RootClass attribute no longer ignores failure to load a module,
1558    but also doesn't try to load a module if the class already exists,
1559    with thanks to James FitzGibbon.
1560  HandleError attribute works for connect failures thanks to David Wheeler.
1561  The connect() RaiseError/PrintError message now includes the username.
1562  Changed "last handle unknown or destroyed" warning to be a trace message.
1563  Removed undocumented $h->event() method.
1564  Further enhancements to DBD::PurePerl accuracy.
1565  The CursorName attribute now defaults to undef and not an error.
1566
1567  DBI::Profile changes:
1568    New DBI::ProfileDumper, DBI::ProfileDumper::Apache, and
1569    DBI::ProfileData modules (to manage the storage and processing
1570    of profile data), plus dbiprof program for analyzing profile
1571    data - with many thanks to Sam Tregar.
1572    Added $DBI::err (etc) tied variable lookup time to profile.
1573    Added time for DESTROY method into parent handles profile (used to be ignored).
1574
1575  Documentation changes:
1576    Documented $dbh = $sth->{Database} attribute.
1577    Documented $dbh->connected(...) post-connection call when subclassing.
1578    Updated some minor doc issues thanks to H.Merijn Brand.
1579    Updated Makefile.PL example in DBI::DBD thanks to KAWAI,Takanori.
1580    Fixed execute_array() example thanks to Peter van Hardenberg.
1581
1582  Changes for driver authors, not required but strongly recommended:
1583    Change DBIS to DBIc_DBISTATE(imp_xxh)   [or imp_dbh, imp_sth etc]
1584    Change DBILOGFP to DBIc_LOGPIO(imp_xxh) [or imp_dbh, imp_sth etc]
1585    Any function from which all instances of DBIS and DBILOGFP are
1586    removed can also have dPERLINTERP removed (a good thing).
1587    All use of the DBIh_EVENT* macros should be removed.
1588    Major update to DBI::DBD docs thanks largely to Jonathan Leffler.
1589    Add these key values: 'Err' => \my $err, 'Errstr' => \my $errstr,
1590    to the hash passed to DBI::_new_dbh() in your driver source code.
1591    That will make each $dbh have it's own $h->err and $h->errstr
1592    values separate from other $dbh belonging to the same driver.
1593    If you have a ::db or ::st DESTROY methods that do nothing
1594    you can now remove them - which speeds up handle destruction.
1595
1596
1597=head2 Changes in DBI 1.30,    18th July 2002
1598
1599  Fixed problems with selectrow_array, selectrow_arrayref, and
1600    selectall_arrayref introduced in DBI 1.29.
1601  Fixed FETCHing a handle attribute to not clear $DBI::err etc (broken in 1.29).
1602  Fixed core dump at trace level 9 or above.
1603  Fixed compilation with perl 5.6.1 + ithreads (i.e. Windows).
1604  Changed definition of behaviour of selectrow_array when called in a scalar
1605    context to match fetchrow_array.
1606  Corrected selectrow_arrayref docs which showed selectrow_array thanks to Paul DuBois.
1607
1608=head2 Changes in DBI 1.29,    15th July 2002
1609
1610  NOTE: This release changes the specified behaviour for the
1611  : fetchrow_array method when called in a scalar context:
1612  : The DBI spec used to say that it would return the FIRST field.
1613  : Which field it returns (i.e., the first or the last) is now undefined.
1614  : This does not affect statements that only select one column, which is
1615  : usually the case when fetchrow_array is called in a scalar context.
1616  : FYI, this change was triggered by discovering that the fetchrow_array
1617  : implementation in Driver.xst (used by most compiled drivers)
1618  : didn't match the DBI specification. Rather than change the code
1619  : to match, and risk breaking existing applications, I've changed the
1620  : specification (that part was always of dubious value anyway).
1621
1622  NOTE: Future versions of the DBI may not support for perl 5.5 much longer.
1623  : If you are still using perl 5.005_03 you should be making plans to
1624  : upgrade to at least perl 5.6.1, or 5.8.0. Perl 5.8.0 is due to be
1625  : released in the next week or so.  (Although it's a "point 0" release,
1626  : it is the most thoroughly tested release ever.)
1627
1628  Added XS/C implementations of selectrow_array, selectrow_arrayref, and
1629    selectall_arrayref to Driver.xst. See DBI 1.26 Changes for more info.
1630  Removed support for the old (fatally flawed) "5005" threading model.
1631  Added support for new perl 5.8 iThreads thanks to Gerald Richter.
1632    (Threading support and safety should still be regarded as beta
1633    quality until further notice. But it's much better than it was.)
1634  Updated the "Threads and Thread Safety" section of the docs.
1635  The trace output can be sent to STDOUT instead of STDERR by using
1636    "STDOUT" as the name of the file, i.e., $h->trace(..., "STDOUT")
1637  Added pointer to perlreftut, perldsc, perllol, and perlboot manuals
1638    into the intro section of the docs, suggested by Brian McCain.
1639  Fixed DBI::Const::GetInfo::* pod docs thanks to Zack Weinberg.
1640  Some changes to how $dbh method calls are treated by DBI::Profile:
1641    Meta-data methods now clear $dbh->{Statement} on entry.
1642    Some $dbh methods are now profiled as if $dbh->{Statement} was empty
1643    (because thet're unlikely to actually relate to its contents).
1644  Updated dbiport.h to ppport.h from perl 5.8.0.
1645  Tested with perl 5.5.3 (vanilla, Solaris), 5.6.1 (vanilla, Solaris), and
1646    perl 5.8.0 (RC3@17527 with iThreads & Multiplicity on Solaris and FreeBSD).
1647
1648=head2 Changes in DBI 1.28,    14th June 2002
1649
1650  Added $sth->{ParamValues} to return a hash of the most recent
1651    values bound to placeholders via bind_param() or execute().
1652    Individual drivers need to be updated to support it.
1653  Enhanced ShowErrorStatement to include ParamValues if available:
1654    "DBD::foo::st execute failed: errstr [for statement ``...'' with params: 1='foo']"
1655  Further enhancements to DBD::PurePerl accuracy.
1656
1657=head2 Changes in DBI 1.27,    13th June 2002
1658
1659  Fixed missing column in C implementation of fetchall_arrayref()
1660    thanks to Philip Molter for the prompt reporting of the problem.
1661
1662=head2 Changes in DBI 1.26,    13th June 2002
1663
1664  Fixed t/40profile.t to work on Windows thanks to Smejkal Petr.
1665  Fixed $h->{Profile} to return undef, not error, if not set.
1666  Fixed DBI->available_drivers in scalar context thanks to Michael Schwern.
1667
1668  Added C implementations of selectrow_arrayref() and fetchall_arrayref()
1669    in Driver.xst.  All compiled drivers using Driver.xst will now be
1670    faster making those calls. Most noticeable with fetchall_arrayref for
1671    many rows or selectrow_arrayref with a fast query. For example, using
1672    DBD::mysql a selectrow_arrayref for a single row using a primary key
1673    is ~20% faster, and fetchall_arrayref for 20000 rows is twice as fast!
1674    Drivers just need to be recompiled and reinstalled to enable it.
1675    The fetchall_arrayref speed up only applies if $slice parameter is not used.
1676  Added $max_rows parameter to fetchall_arrayref() to optionally limit
1677    the number of rows returned. Can now fetch batches of rows.
1678  Added MaxRows attribute to selectall_arrayref()
1679    which then passes it to fetchall_arrayref().
1680  Changed selectrow_array to make use of selectrow_arrayref.
1681  Trace level 1 now shows first two parameters of all methods
1682    (used to only for that for some, like prepare,execute,do etc)
1683  Trace indicator for recursive calls (first char on trace lines)
1684    now starts at 1 not 2.
1685
1686  Documented that $h->func() does not trigger RaiseError etc
1687    so applications must explicitly check for errors.
1688  DBI::Profile with DBI_PROFILE now shows percentage time inside DBI.
1689  HandleError docs updated to show that handler can edit error message.
1690  HandleError subroutine interface is now regarded as stable.
1691
1692=head2 Changes in DBI 1.25,    5th June 2002
1693
1694  Fixed build problem on Windows and some compiler warnings.
1695  Fixed $dbh->{Driver} and $sth->{Statement} for driver internals
1696    These are 'inner' handles as per behaviour prior to DBI 1.16.
1697  Further minor improvements to DBI::PurePerl accuracy.
1698
1699=head2 Changes in DBI 1.24,    4th June 2002
1700
1701  Fixed reference loop causing a handle/memory leak
1702    that was introduced in DBI 1.16.
1703  Fixed DBI::Format to work with 'filehandles' from IO::Scalar
1704    and similar modules thanks to report by Jeff Boes.
1705  Fixed $h->func for DBI::PurePerl thanks to Jeff Zucker.
1706  Fixed $dbh->{Name} for DBI::PurePerl thanks to Dean Arnold.
1707
1708  Added DBI method call profiling and benchmarking.
1709    This is a major new addition to the DBI.
1710    See $h->{Profile} attribute and DBI::Profile module.
1711    For a quick trial, set the DBI_PROFILE environment variable and
1712    run your favourite DBI script. Try it with DBI_PROFILE set to 1,
1713    then try 2, 4, 8, 10, and -10. Have fun!
1714
1715  Added execute_array() and bind_param_array() documentation
1716    with thanks to Dean Arnold.
1717  Added notes about the DBI having not yet been tested with iThreads
1718    (testing and patches for SvLOCK etc welcome).
1719  Removed undocumented Handlers attribute (replaced by HandleError).
1720  Tested with 5.5.3 and 5.8.0 RC1.
1721
1722=head2 Changes in DBI 1.23,    25th May 2002
1723
1724  Greatly improved DBI::PurePerl in performance and accuracy.
1725  Added more detail to DBI::PurePerl docs about what's not supported.
1726  Fixed undef warnings from t/15array.t and DBD::Sponge.
1727
1728=head2 Changes in DBI 1.22,    22nd May 2002
1729
1730  Added execute_array() and bind_param_array() with special thanks
1731    to Dean Arnold. Not yet documented. See t/15array.t for examples.
1732    All drivers now automatically support these methods.
1733  Added DBI::PurePerl, a transparent DBI emulation for pure-perl drivers
1734    with special thanks to Jeff Zucker. Perldoc DBI::PurePerl for details.
1735  Added DBI::Const::GetInfo* modules thanks to Steffen Goeldner.
1736  Added write_getinfo_pm utility to DBI::DBD thanks to Steffen Goeldner.
1737  Added $allow_active==2 mode for prepare_cached() thanks to Stephen Clouse.
1738
1739  Updated DBI::Format to Revision 11.4 thanks to Tom Lowery.
1740  Use File::Spec in Makefile.PL (helps VMS etc) thanks to Craig Berry.
1741  Extend $h->{Warn} to commit/rollback ineffective warning thanks to Jeff Baker.
1742  Extended t/preparse.t and removed "use Devel::Peek" thanks to Scott Hildreth.
1743  Only copy Changes to blib/lib/Changes.pm once thanks to Jonathan Leffler.
1744  Updated internals for modern perls thanks to Jonathan Leffler and Jeff Urlwin.
1745  Tested with perl 5.7.3 (just using default perl config).
1746
1747  Documentation changes:
1748
1749  Added 'Catalog Methods' section to docs thanks to Steffen Goeldner.
1750  Updated README thanks to Michael Schwern.
1751  Clarified that driver may choose not to start new transaction until
1752    next use of $dbh after commit/rollback.
1753  Clarified docs for finish method.
1754  Clarified potentials problems with prepare_cached() thanks to Stephen Clouse.
1755
1756
1757=head2 Changes in DBI 1.21,    7th February 2002
1758
1759  The minimum supported perl version is now 5.005_03.
1760
1761  Fixed DBD::Proxy support for AutoCommit thanks to Jochen Wiedmann.
1762  Fixed DBI::ProxyServer bind_param(_inout) handing thanks to Oleg Mechtcheriakov.
1763  Fixed DBI::ProxyServer fetch loop thanks to nobull@mail.com.
1764  Fixed install_driver do-the-right-thing with $@ on error. It, and connect(),
1765    will leave $@ empty on success and holding the error message on error.
1766    Thanks to Jay Lawrence, Gavin Sherlock and others for the bug report.
1767  Fixed fetchrow_hashref to assign columns to the hash left-to-right
1768    so later fields with the same name overwrite earlier ones
1769    as per DBI < 1.15, thanks to Kay Roepke.
1770
1771  Changed tables() to use quote_indentifier() if the driver returns a
1772    true value for $dbh->get_info(29) # SQL_IDENTIFIER_QUOTE_CHAR
1773  Changed ping() so it no longer triggers RaiseError/PrintError.
1774  Changed connect() to not call $class->install_driver unless needed.
1775  Changed DESTROY to catch fatal exceptions and append to $@.
1776
1777  Added ISO SQL/CLI & ODBCv3 data type definitions thanks to Steffen Goeldner.
1778  Removed the definition of SQL_BIGINT data type constant as the value is
1779    inconsistent between standards (ODBC=-5, SQL/CLI=25).
1780  Added $dbh->column_info(...) thanks to Steffen Goeldner.
1781  Added $dbh->foreign_key_info(...) thanks to Steffen Goeldner.
1782  Added $dbh->quote_identifier(...) insipred by Simon Oliver.
1783  Added $dbh->set_err(...) for DBD authors and DBI subclasses
1784    (actually been there for a while, now expanded and documented).
1785  Added $h->{HandleError} = sub { ... } addition and/or alternative
1786    to RaiseError/PrintError. See the docs for more info.
1787  Added $h->{TraceLevel} = N attribute to set/get trace level of handle
1788    thus can set trace level via an (eg externally specified) DSN
1789    using the embedded attribute syntax:
1790      $dsn = 'dbi:DB2(PrintError=1,TraceLevel=2):dbname';
1791    Plus, you can also now do: local($h->{TraceLevel}) = N;
1792    (but that leaks a little memory in some versions of perl).
1793  Added some call tree information to trace output if trace level >= 3
1794    With thanks to Graham Barr for the stack walking code.
1795  Added experimental undocumented $dbh->preparse(), see t/preparse.t
1796    With thanks to Scott T. Hildreth for much of the work.
1797  Added Fowler/Noll/Vo hash type as an option to DBI::hash().
1798
1799  Documentation changes:
1800
1801  Added DBI::Changes so now you can "perldoc DBI::Changes", yeah!
1802  Added selectrow_arrayref & selectrow_hashref docs thanks to Doug Wilson.
1803  Added 'Standards Reference Information' section to docs to gather
1804    together all references to relevant on-line standards.
1805  Added link to poop.sourceforge.net into the docs thanks to Dave Rolsky.
1806  Added link to hyperlinked BNF for SQL92 thanks to Jeff Zucker.
1807  Added 'Subclassing the DBI' docs thanks to Stephen Clouse, and
1808    then changed some of them to reflect the new approach to subclassing.
1809  Added stronger wording to description of $h->{private_*} attributes.
1810  Added docs for DBI::hash.
1811
1812  Driver API changes:
1813
1814  Now a COPY of the DBI->connect() attributes is passed to the driver
1815    connect() method, so it can process and delete any elements it wants.
1816    Deleting elements reduces/avoids the explicit
1817      $dbh->{$_} = $attr->{$_} foreach keys %$attr;
1818    that DBI->connect does after the driver connect() method returns.
1819
1820
1821=head2 Changes in DBI 1.20,    24th August 2001
1822
1823  WARNING: This release contains two changes that may affect your code.
1824  : Any code using selectall_hashref(), which was added in March 2001, WILL
1825  : need to be changed. Any code using fetchall_arrayref() with a non-empty
1826  : hash slice parameter may, in a few rare cases, need to be changed.
1827  : See the change list below for more information about the changes.
1828  : See the DBI documentation for a description of current behaviour.
1829
1830  Fixed memory leak thanks to Toni Andjelkovic.
1831  Changed fetchall_arrayref({ foo=>1, ...}) specification again (sorry):
1832    The key names of the returned hashes is identical to the letter case of
1833    the names in the parameter hash, regardless of the L</FetchHashKeyName>
1834    attribute. The letter case is ignored for matching.
1835  Changed fetchall_arrayref([...]) array slice syntax specification to
1836    clarify that the numbers in the array slice are perl index numbers
1837    (which start at 0) and not column numbers (which start at 1).
1838  Added { Columns=>... } and { Slice =>... } attributes to selectall_arrayref()
1839    which is passed to fetchall_arrayref() so it can fetch hashes now.
1840  Added a { Columns => [...] } attribute to selectcol_arrayref() so that
1841    the list it returns can be built from more than one column per row.
1842    Why? Consider my %hash = @{$dbh->selectcol_arrayref($sql,{ Columns=>[1,2]})}
1843    to return id-value pairs which can be used directly to build a hash.
1844  Added $hash_ref = $sth->fetchall_hashref( $key_field )
1845    which returns a ref to a hash with, typically, one element per row.
1846    $key_field is the name of the field to get the key for each row from.
1847    The value of the hash for each row is a hash returned by fetchrow_hashref.
1848  Changed selectall_hashref to return a hash ref (from fetchall_hashref)
1849    and not an array of hashes as it has since DBI 1.15 (end March 2001).
1850    WARNING: THIS CHANGE WILL BREAK ANY CODE USING selectall_hashref()!
1851    Sorry, but I think this is an important regularization of the API.
1852    To get previous selectall_hashref() behaviour (an array of hash refs)
1853    change $ary_ref = $dbh->selectall_hashref( $statement, undef, @bind);
1854	to $ary_ref = $dbh->selectall_arrayref($statement, { Columns=>{} }, @bind);
1855  Added NAME_lc_hash, NAME_uc_hash, NAME_hash statement handle attributes.
1856    which return a ref to a hash of field_name => field_index (0..n-1) pairs.
1857  Fixed select_hash() example thanks to Doug Wilson.
1858  Removed (unbundled) DBD::ADO and DBD::Multiplex from the DBI distribution.
1859    The latest versions of those modules are available from CPAN sites.
1860  Added $dbh->begin_work. This method causes AutoCommit to be turned
1861    off just until the next commit() or rollback().
1862    Driver authors: if the DBIcf_BegunWork flag is set when your commit or
1863    rollback method is called then please turn AutoCommit on and clear the
1864    DBIcf_BegunWork flag. If you don't then the DBI will but it'll be much
1865    less efficient and won't handle error conditions very cleanly.
1866  Retested on perl 5.4.4, but the DBI won't support 5.4.x much longer.
1867  Added text to SUPPORT section of the docs:
1868    For direct DBI and DBD::Oracle support, enhancement, and related work
1869    I am available for consultancy on standard commercial terms.
1870  Added text to ACKNOWLEDGEMENTS section of the docs:
1871    Much of the DBI and DBD::Oracle was developed while I was Technical
1872    Director (CTO) of the Paul Ingram Group (www.ig.co.uk).  So I'd
1873    especially like to thank Paul for his generosity and vision in
1874    supporting this work for many years.
1875
1876=head2 Changes in DBI 1.19,    20th July 2001
1877
1878  Made fetchall_arrayref({ foo=>1, ...}) be more strict to the specification
1879    in relation to wanting hash slice keys to be lowercase names.
1880    WARNING: If you've used fetchall_arrayref({...}) with a hash slice
1881    that contains keys with uppercase letters then your code will break.
1882    (As far as I recall the spec has always said don't do that.)
1883  Fixed $sth->execute() to update $dbh->{Statement} to $sth->{Statement}.
1884  Added row number to trace output for fetch method calls.
1885  Trace level 1 no longer shows fetches with row>1 (to reduce output volume).
1886  Added $h->{FetchHashKeyName} = 'NAME_lc' or 'NAME_uc' to alter
1887    behaviour of fetchrow_hashref() method. See docs.
1888  Added type_info quote caching to quote() method thanks to Dean Kopesky.
1889    Makes using quote() with second data type param much much faster.
1890  Added type_into_all() caching to type_info(), spotted by Dean Kopesky.
1891  Added new API definition for table_info() and tables(),
1892    driver authors please note!
1893  Added primary_key_info() to DBI API thanks to Steffen Goeldner.
1894  Added primary_key() to DBI API as simpler interface to primary_key_info().
1895  Indent and other fixes for DBI::DBD doc thanks to H.Merijn Brand.
1896  Added prepare_cached() insert_hash() example thanks to Doug Wilson.
1897  Removed false docs for fetchall_hashref(), use fetchall_arrayref({}).
1898
1899=head2 Changes in DBI 1.18,    4th June 2001
1900
1901  Fixed that altering ShowErrorStatement also altered AutoCommit!
1902    Thanks to Jeff Boes for spotting that clanger.
1903  Fixed DBD::Proxy to handle commit() and rollback(). Long overdue, sorry.
1904  Fixed incompatibility with perl 5.004 (but no one's using that right? :)
1905  Fixed connect_cached and prepare_cached to not be affected by the order
1906    of elements in the attribute hash. Spotted by Mitch Helle-Morrissey.
1907  Fixed version number of DBI::Shell
1908    reported by Stuhlpfarrer Gerhard and others.
1909  Defined and documented table_info() attribute semantics (ODBC compatible)
1910    thanks to Olga Voronova, who also implemented then in DBD::Oracle.
1911  Updated Win32::DBIODBC (Win32::ODBC emulation) thanks to Roy Lee.
1912
1913=head2 Changes in DBI 1.16,    30th May 2001
1914
1915  Reimplemented fetchrow_hashref in C, now fetches about 25% faster!
1916  Changed behaviour if both PrintError and RaiseError are enabled
1917    to simply do both (in that order, obviously :)
1918  Slight reduction in DBI handle creation overhead.
1919  Fixed $dbh->{Driver} & $sth->{Database} to return 'outer' handles.
1920  Fixed execute param count check to honour RaiseError spotted by Belinda Giardie.
1921  Fixed build for perl5.6.1 with PERLIO thanks to H.Merijn Brand.
1922  Fixed client sql restrictions in ProxyServer.pm thanks to Jochen Wiedmann.
1923  Fixed batch mode command parsing in Shell thanks to Christian Lemburg.
1924  Fixed typo in selectcol_arrayref docs thanks to Jonathan Leffler.
1925  Fixed selectrow_hashref to be available to callers thanks to T.J.Mather.
1926  Fixed core dump if statement handle didn't define Statement attribute.
1927  Added bind_param_inout docs to DBI::DBD thanks to Jonathan Leffler.
1928  Added note to data_sources() method docs that some drivers may
1929    require a connected database handle to be supplied as an attribute.
1930  Trace of install_driver method now shows path of driver file loaded.
1931  Changed many '||' to 'or' in the docs thanks to H.Merijn Brand.
1932  Updated DBD::ADO again (improvements in error handling) from Tom Lowery.
1933  Updated Win32::DBIODBC (Win32::ODBC emulation) thanks to Roy Lee.
1934  Updated email and web addresses in DBI::FAQ thanks to Michael A Chase.
1935
1936=head2 Changes in DBI 1.15,    28th March 2001
1937
1938  Added selectrow_arrayref
1939  Added selectrow_hashref
1940  Added selectall_hashref thanks to Leon Brocard.
1941  Added DBI->connect(..., { dbi_connect_method => 'method' })
1942  Added $dbh->{Statement} aliased to most recent child $sth->{Statement}.
1943  Added $h->{ShowErrorStatement}=1 to cause the appending of the
1944    relevant Statement text to the RaiseError/PrintError text.
1945  Modified type_info to always return hash keys in uppercase and
1946    to not require uppercase 'DATA_TYPE' key from type_info_all.
1947    Thanks to Jennifer Tong and Rob Douglas.
1948  Added \%attr param to tables() and table_info() methods.
1949  Trace method uses warn() if it can't open the new file.
1950  Trace shows source line and filename during global destruction.
1951  Updated packages:
1952    Updated Win32::DBIODBC (Win32::ODBC emulation) thanks to Roy Lee.
1953    Updated DBD::ADO to much improved version 0.4 from Tom Lowery.
1954    Updated DBD::Sponge to include $sth->{PRECISION} thanks to Tom Lowery.
1955    Changed DBD::ExampleP to use lstat() instead of stat().
1956  Documentation:
1957    Documented $DBI::lasth (which has been there since day 1).
1958    Documented SQL_* names.
1959    Clarified and extended docs for $h->state thanks to Masaaki Hirose.
1960    Clarified fetchall_arrayref({}) docs (thanks to, er, someone!).
1961    Clarified type_info_all re lettercase and index values.
1962    Updated DBI::FAQ to 0.38 thanks to Alligator Descartes.
1963    Added cute bind_columns example thanks to H.Merijn Brand.
1964    Extended docs on \%attr arg to data_sources method.
1965  Makefile.PL
1966    Removed obscure potential 'rm -rf /' (thanks to Ulrich Pfeifer).
1967    Removed use of glob and find (thanks to Michael A. Chase).
1968  Proxy:
1969    Removed debug messages from DBD::Proxy AUTOLOAD thanks to Brian McCauley.
1970    Added fix for problem using table_info thanks to Tom Lowery.
1971    Added better determination of where to put the pid file, and...
1972    Added KNOWN ISSUES section to DBD::Proxy docs thanks to Jochen Wiedmann.
1973  Shell:
1974    Updated DBI::Format to include DBI::Format::String thanks to Tom Lowery.
1975    Added describe command thanks to Tom Lowery.
1976    Added columnseparator option thanks to Tom Lowery (I think).
1977    Added 'raw' format thanks to, er, someone, maybe Tom again.
1978  Known issues:
1979    Perl 5.005 and 5.006 both leak memory doing local($handle->{Foo}).
1980    Perl 5.004 doesn't. The leak is not a DBI or driver bug.
1981
1982=head2 Changes in DBI 1.14,	14th June 2000
1983
1984  NOTE: This version is the one the DBI book is based on.
1985  NOTE: This version requires at least Perl 5.004.
1986  Perl 5.6 ithreads changes with thanks to Doug MacEachern.
1987  Changed trace output to use PerlIO thanks to Paul Moore.
1988  Fixed bug in RaiseError/PrintError handling.
1989    (% chars in the error string could cause a core dump.)
1990  Fixed Win32 PerlEx IIS concurrency bugs thanks to Murray Nesbitt.
1991  Major documentation polishing thanks to Linda Mui at O'Reilly.
1992  Password parameter now shown as **** in trace output.
1993  Added two fields to type_info and type_info_all.
1994  Added $dsn to PrintError/RaiseError message from DBI->connect().
1995  Changed prepare_cached() croak to carp if sth still Active.
1996  Added prepare_cached() example to the docs.
1997  Added further DBD::ADO enhancements from Thomas Lowery.
1998
1999=head2 Changes in DBI 1.13,	11th July 1999
2000
2001  Fixed Win32 PerlEx IIS concurrency bugs thanks to Murray Nesbitt.
2002  Fixed problems with DBD::ExampleP long_list test mode.
2003  Added SQL_WCHAR SQL_WVARCHAR SQL_WLONGVARCHAR and SQL_BIT
2004    to list of known and exportable SQL types.
2005  Improved data fetch performance of DBD::ADO.
2006  Added GetTypeInfo to DBD::ADO thanks to Thomas Lowery.
2007  Actually documented connect_cached thanks to Michael Schwern.
2008  Fixed user/key/cipher bug in ProxyServer thanks to Joshua Pincus.
2009
2010=head2 Changes in DBI 1.12,	29th June 1999
2011
2012  Fixed significant DBD::ADO bug (fetch skipped first row).
2013  Fixed ProxyServer bug handling non-select statements.
2014  Fixed VMS problem with t/examp.t thanks to Craig Berry.
2015  Trace only shows calls to trace_msg and _set_fbav at high levels.
2016  Modified t/examp.t to workaround Cygwin buffering bug.
2017
2018=head2 Changes in DBI 1.11,	17th June 1999
2019
2020  Fixed bind_columns argument checking to allow a single arg.
2021  Fixed problems with internal default_user method.
2022  Fixed broken DBD::ADO.
2023  Made default $DBI::rows more robust for some obscure cases.
2024
2025=head2 Changes in DBI 1.10,	14th June 1999
2026
2027  Fixed trace_msg.al error when using Apache.
2028  Fixed dbd_st_finish enhancement in Driver.xst (internals).
2029  Enable drivers to define default username and password
2030    and temporarily disabled warning added in 1.09.
2031  Thread safety optimised for single thread case.
2032
2033=head2 Changes in DBI 1.09,	9th June 1999
2034
2035  Added optional minimum trace level parameter to trace_msg().
2036  Added warning in Makefile.PL that DBI will require 5.004 soon.
2037  Added $dbh->selectcol_arrayref($statement) method.
2038  Fixed fetchall_arrayref hash-slice mode undef NAME problem.
2039  Fixed problem with tainted parameter checking and t/examp.t.
2040  Fixed problem with thread safety code, including 64 bit machines.
2041  Thread safety now enabled by default for threaded perls.
2042  Enhanced code for MULTIPLICITY/PERL_OBJECT from ActiveState.
2043  Enhanced prepare_cached() method.
2044  Minor changes to trace levels (less internal info at level 2).
2045  Trace log now shows "!! ERROR..." before the "<- method" line.
2046  DBI->connect() now warn's if user / password is undefined and
2047    DBI_USER / DBI_PASS environment variables are not defined.
2048  The t/proxy.t test now ignores any /etc/dbiproxy.conf file.
2049  Added portability fixes for MacOS from Chris Nandor.
2050  Updated mailing list address from fugue.com to isc.org.
2051
2052=head2 Changes in DBI 1.08,	12th May 1999
2053
2054  Much improved DBD::ADO driver thanks to Phlip Plumlee and others.
2055  Connect now allows you to specify attribute settings within the DSN
2056    E.g., "dbi:Driver(RaiseError=>1,Taint=>1,AutoCommit=>0):dbname"
2057  The $h->{Taint} attribute now also enables taint checking of
2058    arguments to almost all DBI methods.
2059  Improved trace output in various ways.
2060  Fixed bug where $sth->{NAME_xx} was undef in some situations.
2061  Fixed code for MULTIPLICITY/PERL_OBJECT thanks to Alex Smishlajev.
2062  Fixed and documented DBI->connect_cached.
2063  Workaround for Cygwin32 build problem with help from Jong-Pork Park.
2064  bind_columns no longer needs undef or hash ref as first parameter.
2065
2066=head2 Changes in DBI 1.07,	6th May 1999
2067
2068  Trace output now shows contents of array refs returned by DBI.
2069  Changed names of some result columns from type_info, type_info_all,
2070    tables and table_info to match ODBC 3.5 / ISO/IEC standards.
2071  Many fixes for DBD::Proxy and ProxyServer.
2072  Fixed error reporting in install_driver.
2073  Major enhancement to DBI::W32ODBC from Patrick Hollins.
2074  Added $h->{Taint} to taint fetched data if tainting (perl -T).
2075  Added code for MULTIPLICITY/PERL_OBJECT contributed by ActiveState.
2076  Added $sth->more_results (undocumented for now).
2077
2078=head2 Changes in DBI 1.06,	6th January 1999
2079
2080  Fixed Win32 Makefile.PL problem in 1.04 and 1.05.
2081  Significant DBD::Proxy enhancements and fixes
2082    including support for bind_param_inout (Jochen and I)
2083  Added experimental DBI->connect_cached method.
2084  Added $sth->{NAME_uc} and $sth->{NAME_lc} attributes.
2085  Enhanced fetchrow_hashref to take an attribute name arg.
2086
2087=head2 Changes in DBI 1.05,	4th January 1999
2088
2089  Improved DBD::ADO connect (thanks to Phlip Plumlee).
2090  Improved thread safety (thanks to Jochen Wiedmann).
2091  [Quick release prompted by truncation of copies on CPAN]
2092
2093=head2 Changes in DBI 1.04,	3rd January 1999
2094
2095  Fixed error in Driver.xst. DBI build now tests Driver.xst.
2096  Removed unused variable compiler warnings in Driver.xst.
2097  DBI::DBD module now tested during DBI build.
2098  Further clarification in the DBI::DBD driver writers manual.
2099  Added optional name parameter to $sth->fetchrow_hashref.
2100
2101=head2 Changes in DBI 1.03,	1st January 1999
2102
2103  Now builds with Perl>=5.005_54 (PERL_POLLUTE in DBIXS.h)
2104  DBI trace trims path from "at yourfile.pl line nnn".
2105  Trace level 1 now shows statement passed to prepare.
2106  Assorted improvements to the DBI manual.
2107  Assorted improvements to the DBI::DBD driver writers manual.
2108  Fixed $dbh->quote prototype to include optional $data_type.
2109  Fixed $dbh->prepare_cached problems.
2110  $dbh->selectrow_array behaves better in scalar context.
2111  Added a (very) experimental DBD::ADO driver for Win32 ADO.
2112  Added experimental thread support (perl Makefile.PL -thread).
2113  Updated the DBI::FAQ - thanks to Alligator Descartes.
2114  The following changes were implemented and/or packaged
2115    by Jochen Wiedmann - thanks Jochen:
2116  Added a Bundle for CPAN installation of DBI, the DBI proxy
2117    server and prerequisites (lib/Bundle/DBI.pm).
2118  DBI->available_drivers uses File::Spec, if available.
2119    This makes it work on MacOS. (DBI.pm)
2120  Modified type_info to work with read-only values returned
2121    by type_info_all. (DBI.pm)
2122  Added handling of magic values in $sth->execute,
2123    $sth->bind_param and other methods (Driver.xst)
2124  Added Perl's CORE directory to the linkers path on Win32,
2125    required by recent versions of ActiveState Perl.
2126  Fixed DBD::Sponge to work with empty result sets.
2127  Complete rewrite of DBI::ProxyServer and DBD::Proxy.
2128
2129=head2 Changes in DBI 1.02,	2nd September 1998
2130
2131  Fixed DBI::Shell including @ARGV and /current.
2132  Added basic DBI::Shell test.
2133  Renamed DBI::Shell /display to /format.
2134
2135=head2 Changes in DBI 1.01,	2nd September 1998
2136
2137  Many enhancements to Shell (with many contributions from
2138  Jochen Wiedmann, Tom Lowery and Adam Marks).
2139  Assorted fixes to DBD::Proxy and DBI::ProxyServer.
2140  Tidied up trace messages - trace(2) much cleaner now.
2141  Added $dbh->{RowCacheSize} and $sth->{RowsInCache}.
2142  Added experimental DBI::Format (mainly for DBI::Shell).
2143  Fixed fetchall_arrayref($slice_hash).
2144  DBI->connect now honours PrintError=1 if connect fails.
2145  Assorted clarifications to the docs.
2146
2147=head2 Changes in DBI 1.00,	14th August 1998
2148
2149  The DBI is no longer 'alpha' software!
2150  Added $dbh->tables and $dbh->table_info.
2151  Documented \%attr arg to data_sources method.
2152  Added $sth->{TYPE}, $sth->{PRECISION} and $sth->{SCALE}.
2153  Added $sth->{Statement}.
2154  DBI::Shell now uses neat_list to print results
2155  It also escapes "'" chars and converts newlines to spaces.
2156
2157=head2 Changes in DBI 0.95,	10th August 1998
2158
2159  WARNING: THIS IS AN EXPERIMENTAL RELEASE!
2160
2161  Fixed 0.94 slip so it will build on pre-5.005 again.
2162  Added DBI_AUTOPROXY environment variable.
2163  Array ref returned from fetch/fetchrow_arrayref now readonly.
2164  Improved connect error reporting by DBD::Proxy.
2165  All trace/debug messages from DBI now go to trace file.
2166
2167=head2 Changes in DBI 0.94,	9th August 1998
2168
2169  WARNING: THIS IS AN EXPERIMENTAL RELEASE!
2170
2171  Added DBD::Shell and dbish interactive DBI shell. Try it!
2172  Any database attribs can be set via DBI->connect(,,, \%attr).
2173  Added _get_fbav and _set_fbav methods for Perl driver developers
2174    (see ExampleP driver for perl usage). Drivers which don't use
2175    one of these methods (either via XS or Perl) are not compliant.
2176  DBI trace now shows adds " at yourfile.pl line nnn"!
2177  PrintError and RaiseError now prepend driver and method name.
2178  The available_drivers method no longer returns NullP or Sponge.
2179  Added $dbh->{Name}.
2180  Added $dbh->quote($value, $data_type).
2181  Added more hints to install_driver failure message.
2182  Added DBD::Proxy and DBI::ProxyServer (from Jochen Wiedmann).
2183  Added $DBI::neat_maxlen to control truncation of trace output.
2184  Added $dbh->selectall_arrayref and $dbh->selectrow_array methods.
2185  Added $dbh->tables.
2186  Added $dbh->type_info and $dbh->type_info_all.
2187  Added $h->trace_msg($msg) to write to trace log.
2188  Added @bool = DBI::looks_like_number(@ary).
2189  Many assorted improvements to the DBI docs.
2190
2191=head2 Changes in DBI 0.93,	13th February 1998
2192
2193  Fixed DBI::DBD::dbd_postamble bug causing 'Driver.xsi not found' errors.
2194  Changes to handling of 'magic' values in neatsvpv (used by trace).
2195  execute (in Driver.xst) stops binding after first bind error.
2196  This release requires drivers to be rebuilt.
2197
2198=head2 Changes in DBI 0.92,	3rd February 1998
2199
2200  Fixed per-handle memory leak (with many thanks to Irving Reid).
2201  Added $dbh->prepare_cached() caching variant of $dbh->prepare.
2202  Added some attributes:
2203    $h->{Active}       is the handle 'Active' (vague concept) (boolean)
2204    $h->{Kids}         e.g. number of sth's associated with a dbh
2205    $h->{ActiveKids}   number of the above which are 'Active'
2206    $dbh->{CachedKids} ref to prepare_cached sth cache
2207  Added support for general-purpose 'private_' attributes.
2208  Added experimental support for subclassing the DBI: see t/subclass.t
2209  Added SQL_ALL_TYPES to exported :sql_types.
2210  Added dbd_dbi_dir() and dbd_dbi_arch_dir() to DBI::DBD module so that
2211  DBD Makefile.PLs can work with the DBI installed in non-standard locations.
2212  Fixed 'Undefined value' warning and &sv_no output from neatsvpv/trace.
2213  Fixed small 'once per interpreter' leak.
2214  Assorted minor documentation fixes.
2215
2216=head2 Changes in DBI 0.91,	10th December 1997
2217
2218  NOTE: This fix may break some existing scripts:
2219  DBI->connect("dbi:...",$user,$pass) was not setting AutoCommit and PrintError!
2220  DBI->connect(..., { ... }) no longer sets AutoCommit or PrintError twice.
2221  DBI->connect(..., { RaiseError=>1 }) now croaks if connect fails.
2222  Fixed $fh parameter of $sth->dump_results;
2223  Added default statement DESTROY method which carps.
2224  Added default driver DESTROY method to silence AUTOLOAD/__DIE__/CGI::Carp
2225  Added more SQL_* types to %EXPORT_TAGS and @EXPORT_OK.
2226  Assorted documentation updates (mainly clarifications).
2227  Added workaround for perl's 'sticky lvalue' bug.
2228  Added better warning for bind_col(umns) where fields==0.
2229  Fixed to build okay with 5.004_54 with or without USE_THREADS.
2230  Note that the DBI has not been tested for thread safety yet.
2231
2232=head2 Changes in DBI 0.90,	6th September 1997
2233
2234  Can once again be built with Perl 5.003.
2235  The DBI class can be subclassed more easily now.
2236  InactiveDestroy fixed for drivers using the *.xst template.
2237  Slightly faster handle creation.
2238  Changed prototype for dbd_*_*_attrib() to add extra param.
2239  Note: 0.90, 0.89 and possibly some other recent versions have
2240  a small memory leak. This will be fixed in the next release.
2241
2242=head2 Changes in DBI 0.89,	25th July 1997
2243
2244  Minor fix to neatsvpv (mainly used for debug trace) to workaround
2245  bug in perl where SvPV removes IOK flag from an SV.
2246  Minor updates to the docs.
2247
2248=head2 Changes in DBI 0.88,	22nd July 1997
2249
2250  Fixed build for perl5.003 and Win32 with Borland.
2251  Fixed documentation formatting.
2252  Fixed DBI_DSN ignored for old-style connect (with explicit driver).
2253  Fixed AutoCommit in DBD::ExampleP
2254  Fixed $h->trace.
2255  The DBI can now export SQL type values: use DBI ':sql_types';
2256  Modified Driver.xst and renamed DBDI.h to dbd_xsh.h
2257
2258=head2 Changes in DBI 0.87,	18th July 1997
2259
2260  Fixed minor type clashes.
2261  Added more docs about placeholders and bind values.
2262
2263=head2 Changes in DBI 0.86,	16th July 1997
2264
2265  Fixed failed connect causing 'unblessed ref' and other errors.
2266  Drivers must handle AutoCommit FETCH and STORE else DBI croaks.
2267  Added $h->{LongReadLen} and $h->{LongTruncOk} attributes for BLOBS.
2268  Added DBI_USER and DBI_PASS env vars. See connect docs for usage.
2269  Added DBI->trace() to set global trace level (like per-handle $h->trace).
2270  PERL_DBI_DEBUG env var renamed DBI_DEBUG (old name still works for now).
2271  Updated docs, including commit, rollback, AutoCommit and Transactions sections.
2272  Added bind_param method and execute(@bind_values) to docs.
2273  Fixed fetchall_arrayref.
2274
2275  Since the DBIS structure has change the internal version numbers have also
2276  changed (DBIXS_VERSION == 9 and DBISTATE_VERSION == 9) so drivers will have
2277  to be recompiled. The test is also now more sensitive and the version
2278  mismatch error message now more clear about what to do. Old drivers are
2279  likely to core dump (this time) until recompiled for this DBI. In future
2280  DBI/DBD version mismatch will always produce a clear error message.
2281
2282  Note that this DBI release contains and documents many new features
2283  that won't appear in drivers for some time. Driver writers might like
2284  to read perldoc DBI::DBD and comment on or apply the information given.
2285
2286=head2 Changes in DBI 0.85,	25th June 1997
2287
2288  NOTE: New-style connect now defaults to AutoCommit mode unless
2289  { AutoCommit => 0 } specified in connect attributes. See the docs.
2290  AutoCommit attribute now defined and tracked by DBI core.
2291  Drivers should use/honour this and not implement their own.
2292  Added pod doc changes from Andreas and Jonathan.
2293  New DBI_DSN env var default for connect method. See docs.
2294  Documented the func method.
2295  Fixed "Usage: DBD::_::common::DESTROY" error.
2296  Fixed bug which set some attributes true when there value was fetched.
2297  Added new internal DBIc_set() macro for drivers to use.
2298
2299=head2 Changes in DBI 0.84,	20th June 1997
2300
2301  Added $h->{PrintError} attribute which, if set true, causes all errors to
2302  trigger a warn().
2303  New-style DBI->connect call now automatically sets PrintError=1 unless
2304  { PrintError => 0 } specified in the connect attributes. See the docs.
2305  The old-style connect with a separate driver parameter is deprecated.
2306  Fixed fetchrow_hashref.
2307  Renamed $h->debug to $h->trace() and added a trace filename arg.
2308  Assorted other minor tidy-ups.
2309
2310=head2 Changes in DBI 0.83,	11th June 1997
2311
2312  Added driver specification syntax to DBI->connect data_source
2313  parameter: DBI->connect('dbi:driver:...', $user, $passwd);
2314  The DBI->data_sources method should return data_source
2315  names with the appropriate 'dbi:driver:' prefix.
2316  DBI->connect will warn if \%attr is true but not a hash ref.
2317  Added the new fetchrow methods:
2318    @row_ary  = $sth->fetchrow_array;
2319    $ary_ref  = $sth->fetchrow_arrayref;
2320    $hash_ref = $sth->fetchrow_hashref;
2321  The old fetch and fetchrow methods still work.
2322  Driver implementors should implement the new names for
2323  fetchrow_array and fetchrow_arrayref ASAP (use the xs ALIAS:
2324  directive to define aliases for fetch and fetchrow).
2325  Fixed occasional problems with t/examp.t test.
2326  Added automatic errstr reporting to the debug trace output.
2327  Added the DBI FAQ from Alligator Descartes in module form for
2328  easy reading via "perldoc DBI::FAQ". Needs reformatting.
2329  Unknown driver specific attribute names no longer croak.
2330  Fixed problem with internal neatsvpv macro.
2331
2332=head2 Changes in DBI 0.82,	23rd May 1997
2333
2334  Added $h->{RaiseError} attribute which, if set true, causes all errors to
2335  trigger a die(). This makes it much easier to implement robust applications
2336  in terms of higher level eval { ... } blocks and rollbacks.
2337  Added DBI->data_sources($driver) method for implementation by drivers.
2338  The quote method now returns the string NULL (without quotes) for undef.
2339  Added VMS support thanks to Dan Sugalski.
2340  Added a 'quick start guide' to the README.
2341  Added neatsvpv function pointer to DBIS structure to make it available for
2342  use by drivers. A macro defines neatsvpv(sv,len) as (DBIS->neatsvpv(sv,len)).
2343  Old XS macro SV_YES_NO changes to standard boolSV.
2344  Since the DBIS structure has change the internal version numbers have also
2345  changed (DBIXS_VERSION == 8 and DBISTATE_VERSION == 8) so drivers will have
2346  to be recompiled.
2347
2348=head2 Changes in DBI 0.81,	7th May 1997
2349
2350  Minor fix to let DBI build using less modern perls.
2351  Fixed a suprious typo warning.
2352
2353=head2 Changes in DBI 0.80,	6th May 1997
2354
2355  Builds with no changes on NT using perl5.003_99 (with thanks to Jeffrey Urlwin).
2356  Automatically supports Apache::DBI (with thanks to Edmund Mergl).
2357    DBI scripts no longer need to be modified to make use of Apache::DBI.
2358  Added a ping method and an experimental connect_test_perf method.
2359  Added a fetchhash and fetch_all methods.
2360  The func method no longer pre-clears err and errstr.
2361  Added ChopBlanks attribute (currently defaults to off, that may change).
2362    Support for the attribute needs to be implemented by individual drivers.
2363  Reworked tests into standard t/*.t form.
2364  Added more pod text.  Fixed assorted bugs.
2365
2366
2367=head2 Changes in DBI 0.79,	7th Apr 1997
2368
2369  Minor release. Tidied up pod text and added some more descriptions
2370  (especially disconnect). Minor changes to DBI.xs to remove compiler
2371  warnings.
2372
2373=head2 Changes in DBI 0.78,	28th Mar 1997
2374
2375  Greatly extended the pod documentation in DBI.pm, including the under
2376  used bind_columns method. Use 'perldoc DBI' to read after installing.
2377  Fixed $h->err. Fetching an attribute value no longer resets err.
2378  Added $h->{InactiveDestroy}, see documentation for details.
2379  Improved debugging of cached ('quick') attribute fetches.
2380  errstr will return err code value if there is no string value.
2381  Added DBI/W32ODBC to the distribution. This is a pure-perl experimental
2382  DBI emulation layer for Win32::ODBC. Note that it's unsupported, your
2383  mileage will vary, and bug reports without fixes will probably be ignored.
2384
2385=head2 Changes in DBI 0.77,	21st Feb 1997
2386
2387  Removed erroneous $h->errstate and $h->errmsg methods from DBI.pm.
2388  Added $h->err, $h->errstr and $h->state default methods in DBI.xs.
2389  Updated informal DBI API notes in DBI.pm. Updated README slightly.
2390  DBIXS.h now correctly installed into INST_ARCHAUTODIR.
2391  (DBD authors will need to edit their Makefile.PL's to use
2392  -I$(INSTALLSITEARCH)/auto/DBI -I$(INSTALLSITEARCH)/DBI)
2393
2394
2395=head2 Changes in DBI 0.76,	3rd Feb 1997
2396
2397  Fixed a compiler type warnings (pedantic IRIX again).
2398
2399=head2 Changes in DBI 0.75,	27th Jan 1997
2400
2401  Fix problem introduced by a change in Perl5.003_XX.
2402  Updated README and DBI.pm docs.
2403
2404=head2 Changes in DBI 0.74,	14th Jan 1997
2405
2406  Dispatch now sets dbi_debug to the level of the current handle
2407  (this makes tracing/debugging individual handles much easier).
2408  The '>> DISPATCH' log line now only logged at debug >= 3 (was 2).
2409  The $csr->NUM_OF_FIELDS attribute can be set if not >0 already.
2410  You can log to a file using the env var PERL_DBI_DEBUG=/tmp/dbi.log.
2411  Added a type cast needed by IRIX.
2412  No longer sets perl_destruct_level unless debug set >= 4.
2413  Make compatible with PerlIO and sfio.
2414
2415=head2 Changes in DBI 0.73,	10th Oct 1996
2416
2417  Fixed some compiler type warnings (IRIX).
2418  Fixed DBI->internal->{DebugLog} = $filename.
2419  Made debug log file unbuffered.
2420  Added experimental bind_param_inout method to interface.
2421  Usage: $dbh->bind_param_inout($param, \$value, $maxlen [, \%attribs ])
2422  (only currently used by DBD::Oracle at this time.)
2423
2424=head2 Changes in DBI 0.72,	23 Sep 1996
2425
2426  Using an undefined value as a handle now gives a better
2427  error message (mainly useful for emulators like Oraperl).
2428  $dbh->do($sql, @params) now works for binding placeholders.
2429
2430=head2 Changes in DBI 0.71,	10 July 1996
2431
2432  Removed spurious abort() from invalid handle check.
2433  Added quote method to DBI interface and added test.
2434
2435=head2 Changes in DBI 0.70,	16 June 1996
2436
2437  Added extra invalid handle check (dbih_getcom)
2438  Fixed broken $dbh->quote method.
2439  Added check for old GCC in Makefile.PL
2440
2441=head2 Changes in DBI 0.69
2442
2443  Fixed small memory leak.
2444  Clarified the behaviour of DBI->connect.
2445  $dbh->do now returns '0E0' instead of 'OK'.
2446  Fixed "Can't read $DBI::errstr, lost last handle" problem.
2447
2448
2449=head2 Changes in DBI 0.68,	2 Mar 1996
2450
2451  Changes to suit perl5.002 and site_lib directories.
2452  Detects old versions ahead of new in @INC.
2453
2454
2455=head2 Changes in DBI 0.67,	15 Feb 1996
2456
2457  Trivial change to test suite to fix a problem shown up by the
2458  Perl5.002gamma release Test::Harness.
2459
2460
2461=head2 Changes in DBI 0.66,	29 Jan 1996
2462
2463  Minor changes to bring the DBI into line with 5.002 mechanisms,
2464  specifically the xs/pm VERSION checking mechanism.
2465  No functionality changes. One no-last-handle bug fix (rare problem).
2466  Requires 5.002 (beta2 or later).
2467
2468
2469=head2 Changes in DBI 0.65,	23 Oct 1995
2470
2471  Added $DBI::state to hold SQL CLI / ODBC SQLSTATE value.
2472  SQLSTATE "00000" (success) is returned as "" (false), all else is true.
2473  If a driver does not explicitly initialise it (via $h->{State} or
2474  DBIc_STATE(imp_xxh) then $DBI::state will automatically return "" if
2475  $DBI::err is false otherwise "S1000" (general error).
2476  As always, this is a new feature and liable to change.
2477
2478  The is *no longer* a default error handler!
2479  You can add your own using push(@{$h->{Handlers}}, sub { ... })
2480  but be aware that this interface may change (or go away).
2481
2482  The DBI now automatically clears $DBI::err, errstr and state before
2483  calling most DBI methods. Previously error conditions would persist.
2484  Added DBIh_CLEAR_ERROR(imp_xxh) macro.
2485
2486  DBI now EXPORT_OK's some utility functions, neat($value),
2487  neat_list(@values) and dump_results($sth).
2488
2489  Slightly enhanced t/min.t minimal test script in an effort to help
2490  narrow down the few stray core dumps that some porters still report.
2491
2492  Renamed readblob to blob_read (old name still works but warns).
2493  Added default blob_copy_to_file method.
2494
2495  Added $sth = $dbh->tables method. This returns an $sth for a query
2496  which has these columns: TABLE_CATALOGUE, TABLE_OWNER, TABLE_NAME,
2497  TABLE_TYPE, REMARKS in that order. The TABLE_CATALOGUE column
2498  should be ignored for now.
2499
2500
2501=head2 Changes in DBI 0.64,	23 Oct 1995
2502
2503  Fixed 'disconnect invalidates 1 associated cursor(s)' problem.
2504  Drivers using DBIc_ACTIVE_on/off() macros should not need any changes
2505  other than to test for DBIc_ACTIVE_KIDS() instead of DBIc_KIDS().
2506  Fixed possible core dump in dbih_clearcom during global destruction.
2507
2508
2509=head2 Changes in DBI 0.63,	1 Sep 1995
2510
2511  Minor update. Fixed uninitialised memory bug in method
2512  attribute handling and streamlined processing and debugging.
2513  Revised usage definitions for bind_* methods and readblob.
2514
2515
2516=head2 Changes in DBI 0.62,	26 Aug 1995
2517
2518  Added method redirection method $h->func(..., $method_name).
2519  This is now the official way to call private driver methods
2520  that are not part of the DBI standard.  E.g.:
2521      @ary = $sth->func('ora_types');
2522  It can also be used to call existing methods. Has very low cost.
2523
2524  $sth->bind_col columns now start from 1 (not 0) to match SQL.
2525  $sth->bind_columns now takes a leading attribute parameter (or undef),
2526  e.g., $sth->bind_columns($attribs, \$col1 [, \$col2 , ...]);
2527
2528  Added handy DBD_ATTRIBS_CHECK macro to vet attribs in XS.
2529  Added handy DBD_ATTRIB_GET_SVP, DBD_ATTRIB_GET_BOOL and
2530  DBD_ATTRIB_GET_IV macros for handling attributes.
2531
2532  Fixed STORE for NUM_OF_FIELDS and NUM_OF_PARAMS.
2533  Added FETCH for NUM_OF_FIELDS and NUM_OF_PARAMS.
2534
2535  Dispatch no longer bothers to call _untie().
2536  Faster startup via install_method/_add_dispatch changes.
2537
2538
2539=head2 Changes in DBI 0.61,	22 Aug 1995
2540
2541  Added $sth->bind_col($column, \$var [, \%attribs ]);
2542
2543  This method enables perl variable to be directly and automatically
2544  updated when a row is fetched. It requires no driver support
2545  (if the driver has been written to use DBIS->get_fbav).
2546  Currently \%attribs is unused.
2547
2548  Added $sth->bind_columns(\$var [, \$var , ...]);
2549
2550  This method is a short-cut for bind_col which binds all the
2551  columns of a query in one go (with no attributes). It also
2552  requires no driver support.
2553
2554  Added $sth->bind_param($parameter, $var [, \%attribs ]);
2555
2556  This method enables attributes to be specified when values are
2557  bound to placeholders. It also enables binding to occur away
2558  from the execute method to improve execute efficiency.
2559  The DBI does not provide a default implementation of this.
2560  See the DBD::Oracle module for a detailed example.
2561
2562  The DBI now provides default implementations of both fetch and
2563  fetchrow.  Each is written in terms of the other. A driver is
2564  expected to implement at least one of them.
2565
2566  More macro and assorted structure changes in DBDXS.h. Sorry!
2567  The old dbihcom definitions have gone. All fields have macros.
2568  The imp_xxh_t type is now used within the DBI as well as drivers.
2569  Drivers must set DBIc_NUM_FIELDS(imp_sth) and DBIc_NUM_PARAMS(imp_sth).
2570
2571  test.pl includes a trivial test of bind_param and bind_columns.
2572
2573
2574=head2 Changes in DBI 0.60,	17 Aug 1995
2575
2576  This release has significant code changes but much less
2577  dramatic than the previous release. The new implementors data
2578  handling mechanism has matured significantly (don't be put off
2579  by all the struct typedefs in DBIXS.h, there's just to make it
2580  easier for drivers while keeping things type-safe).
2581
2582  The DBI now includes two new methods:
2583
2584  do		$dbh->do($statement)
2585
2586  This method prepares, executes and finishes a statement. It is
2587  designed to be used for executing one-off non-select statements
2588  where there is no benefit in reusing a prepared statement handle.
2589
2590  fetch		$array_ref = $sth->fetch;
2591
2592  This method is the new 'lowest-level' row fetching method. The
2593  previous @row = $sth->fetchrow method now defaults to calling
2594  the fetch method and expanding the returned array reference.
2595
2596  The DBI now provides fallback attribute FETCH and STORE functions
2597  which drivers should call if they don't recognise an attribute.
2598
2599  THIS RELEASE IS A GOOD STARTING POINT FOR DRIVER DEVELOPERS!
2600  Study DBIXS.h from the DBI and Oracle.xs etc from DBD::Oracle.
2601  There will be further changes in the interface but nothing
2602  as dramatic as these last two releases! (I hope :-)
2603
2604
2605=head2 Changes in DBI 0.59	15 Aug 1995
2606
2607  NOTE: THIS IS AN UNSTABLE RELEASE!
2608
2609  Major reworking of internal data management!
2610  Performance improvements and memory leaks fixed.
2611  Added a new NullP (empty) driver and a -m flag
2612  to test.pl to help check for memory leaks.
2613  Study DBD::Oracle version 0.21 for more details.
2614  (Comparing parts of v0.21 with v0.20 may be useful.)
2615
2616
2617=head2 Changes in DBI 0.58	21 June 1995
2618
2619  Added DBI->internal->{DebugLog} = $filename;
2620  Reworked internal logging.
2621  Added $VERSION.
2622  Made disconnect_all a compulsory method for drivers.
2623
2624
2625=head1 ANCIENT HISTORY
2626
262712th Oct 1994: First public release of the DBI module.
2628               (for Perl 5.000-beta-3h)
2629
263019th Sep 1994: DBperl project renamed to DBI.
2631
263229th Sep 1992: DBperl project started.
2633
2634=cut
2635