1*c5c4113dSnw141292The SQL database used for ACD contains 113 tables and indices implemented
2*c5c4113dSnw141292in GDBM.  The following are statistics on the sizes of keys and data
3*c5c4113dSnw141292within these tables and indices.
4*c5c4113dSnw141292
5*c5c4113dSnw141292Entries:      962080
6*c5c4113dSnw141292Size:         45573853
7*c5c4113dSnw141292Avg Size:     48
8*c5c4113dSnw141292Key Size:     11045299
9*c5c4113dSnw141292Avg Key Size: 12
10*c5c4113dSnw141292Max Key Size: 99
11*c5c4113dSnw141292
12*c5c4113dSnw141292
13*c5c4113dSnw141292 Size of key              Cummulative
14*c5c4113dSnw141292  and data     Instances  Percentage
15*c5c4113dSnw141292------------  ----------  -----------
16*c5c4113dSnw141292    0..8            266    0%
17*c5c4113dSnw141292    9..12          5485    0%
18*c5c4113dSnw141292   13..16         73633    8%
19*c5c4113dSnw141292   17..24        180918   27%
20*c5c4113dSnw141292   25..32        209823   48%
21*c5c4113dSnw141292   33..40        148995   64%
22*c5c4113dSnw141292   41..48         76304   72%
23*c5c4113dSnw141292   49..56         14346   73%
24*c5c4113dSnw141292   57..64         15725   75%
25*c5c4113dSnw141292   65..80         44916   80%
26*c5c4113dSnw141292   81..96        127815   93%
27*c5c4113dSnw141292   97..112        34769   96%
28*c5c4113dSnw141292  113..128        13314   98%
29*c5c4113dSnw141292  129..144         8098   99%
30*c5c4113dSnw141292  145..160         3355   99%
31*c5c4113dSnw141292  161..176         1159   99%
32*c5c4113dSnw141292  177..192          629   99%
33*c5c4113dSnw141292  193..208          221   99%
34*c5c4113dSnw141292  209..224          210   99%
35*c5c4113dSnw141292  225..240          129   99%
36*c5c4113dSnw141292  241..256           57   99%
37*c5c4113dSnw141292  257..288          496   99%
38*c5c4113dSnw141292  289..320           60   99%
39*c5c4113dSnw141292  321..352           37   99%
40*c5c4113dSnw141292  353..384           46   99%
41*c5c4113dSnw141292  385..416           22   99%
42*c5c4113dSnw141292  417..448           24   99%
43*c5c4113dSnw141292  449..480           26   99%
44*c5c4113dSnw141292  481..512           27   99%
45*c5c4113dSnw141292  513..1024         471   99%
46*c5c4113dSnw141292 1025..2048         389   99%
47*c5c4113dSnw141292 2049..4096         182   99%
48*c5c4113dSnw141292 4097..8192          74   99%
49*c5c4113dSnw141292 8193..16384         34   99%
50*c5c4113dSnw14129216385..32768         17   99%
51*c5c4113dSnw14129232769..65536          5   99%
52*c5c4113dSnw14129265537..131073         3  100%
53*c5c4113dSnw141292
54*c5c4113dSnw141292
55*c5c4113dSnw141292This information is gathered to help design the new built-in
56*c5c4113dSnw141292backend for sqlite 2.0.  Note in particular that 99% of all
57*c5c4113dSnw141292database entries have a combined key and data size of less than
58*c5c4113dSnw141292144 bytes.  So if a leaf node in the new database is able to
59*c5c4113dSnw141292store 144 bytes of combined key and data, only 1% of the leaves
60*c5c4113dSnw141292will require overflow pages.  Furthermore, note that no key
61*c5c4113dSnw141292is larger than 99 bytes, so if the key will never be on an
62*c5c4113dSnw141292overflow page.
63*c5c4113dSnw141292
64*c5c4113dSnw141292The average combined size of key+data is 48.  Add in 16 bytes of
65*c5c4113dSnw141292overhead for a total of 64.  That means that a 1K page will
66*c5c4113dSnw141292store (on average) about 16 entries.
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