1# 2016 November 11
2#
3# The author disclaims copyright to this source code.  In place of
4# a legal notice, here is a blessing:
5#
6#    May you do good and not evil.
7#    May you find forgiveness for yourself and forgive others.
8#    May you share freely, never taking more than you give.
9#
10#***********************************************************************
11# Test the virtual table interface. In particular the xBestIndex
12# method.
13#
14
15set testdir [file dirname $argv0]
16source $testdir/tester.tcl
17set testprefix bestindex4
18
19ifcapable !vtab {
20  finish_test
21  return
22}
23
24#-------------------------------------------------------------------------
25# Virtual table callback for a virtual table named $tbl.
26#
27# The table created is:
28#
29#      "CREATE TABLE t1 (id, host, class)"
30#
31# The virtual table supports == operators on a subset of its columns. The
32# exact subset depends on the value of bitmask paramater $param.
33#
34#   0x01 - == on "id" supported
35#   0x02 - == on "host" supported
36#   0x04 - == on "class" supported
37#
38# $param also supports the following bits:
39#
40#   0x08 - ignore the "usable" flag (malfunction)
41#
42#
43#
44proc vtab_cmd {param method args} {
45  switch -- $method {
46    xConnect {
47      return "CREATE TABLE t1(id TEXT, host TEXT, class TEXT)"
48    }
49
50    xBestIndex {
51      foreach {clist orderby mask} $args {}
52
53      set ret [list]
54
55      set use use
56
57
58      for {set i 0} {$i < [llength $clist]} {incr i} {
59        array unset C
60        array set C [lindex $clist $i]
61        if { ($C(usable) || ($param & 0x08))
62          && $C(op)=="eq" && ($param & 1<<$C(column))
63        } {
64          lappend ret $use $i
65          break
66        }
67      }
68
69      set score 1000000
70      if {$ret!=""} {
71        set score [expr $score / [llength $ret]]
72      }
73      lappend ret cost $score rows $score
74
75      return $ret
76    }
77
78    xFilter {
79    }
80  }
81  return ""
82}
83
84register_tcl_module db
85
86for {set param1 0} {$param1<16} {incr param1} {
87  for {set param2 0} {$param2<16} {incr param2} {
88    reset_db
89    register_tcl_module db
90    do_execsql_test 1.$param1.$param2.1 "
91      CREATE VIRTUAL TABLE t1 USING tcl('vtab_cmd $param1');
92      CREATE VIRTUAL TABLE t2 USING tcl('vtab_cmd $param2');
93    "
94
95    foreach {tn sql} {
96      2 "select t1.id as ID from t1, t2 where t1.id=t2.host and t2.class='xx'"
97      3 {
98        select t1.id as ID from t1, t2 where t2.class ='xx' and t2.id = t1.host
99      }
100      4 {
101        select t1.id as ID from t1, t2 where t1.host = t2.id and t2. class ='xx'
102      }
103    } {
104
105      if {($param1 & 0x08)==0 && ($param2 & 0x08)==0} {
106
107        do_execsql_test 1.$param1.$param2.$tn.a $sql {}
108
109      } else {
110        do_test 1.$param1.$param2.$tn.b {
111          catchsql $sql
112            set {} {}
113        } {}
114      }
115    }
116
117  }
118}
119
120#-------------------------------------------------------------------------
121# Test that a parameter passed to a table-valued function cannot be
122# used to drive an index. i.e. that in the following:
123#
124#   SELECT * FROM tbl, vtab(tbl.x);
125#
126# The implicit constraint "tbl.x = vtab.hidden" is not optimized using
127# an index on tbl.x.
128#
129reset_db
130register_tcl_module db
131proc vtab_command {method args} {
132  switch -- $method {
133    xConnect {
134      return "CREATE TABLE t1(a, b, c, d HIDDEN)"
135    }
136
137    xBestIndex {
138      set clist [lindex $args 0]
139      if {[llength $clist]!=1} { error "unexpected constraint list" }
140      catch { array unset C }
141      array set C [lindex $clist 0]
142      if {$C(usable)} {
143        return [list omit 0 idxnum 555 rows 10 cost 100]
144      }
145      return [list cost 100000000]
146    }
147
148  }
149
150  return {}
151}
152
153do_execsql_test 2.0 {
154  CREATE VIRTUAL TABLE x1 USING tcl(vtab_command);
155  CREATE TABLE t1 (x INT PRIMARY KEY);
156} {}
157
158do_eqp_test 2.1 {
159  SELECT * FROM t1, x1 WHERE x1.d=t1.x;
160} {
161  QUERY PLAN
162  |--SCAN TABLE x1 VIRTUAL TABLE INDEX 0:
163  `--SEARCH TABLE t1 USING COVERING INDEX sqlite_autoindex_t1_1 (x=?)
164}
165
166do_eqp_test 2.2 {
167  SELECT * FROM t1, x1(t1.x)
168} {
169  QUERY PLAN
170  |--SCAN TABLE t1
171  `--SCAN TABLE x1 VIRTUAL TABLE INDEX 555:
172}
173
174
175finish_test
176