67 lines
2.1 KiB
Plaintext
67 lines
2.1 KiB
Plaintext
The SQL database used for ACD contains 113 tables and indices implemented
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in GDBM. The following are statistics on the sizes of keys and data
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within these tables and indices.
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Entries: 962080
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Size: 45573853
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Avg Size: 48
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Key Size: 11045299
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Avg Key Size: 12
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Max Key Size: 99
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Size of key Cummulative
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and data Instances Percentage
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------------ ---------- -----------
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0..8 266 0%
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9..12 5485 0%
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13..16 73633 8%
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17..24 180918 27%
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25..32 209823 48%
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33..40 148995 64%
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41..48 76304 72%
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49..56 14346 73%
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57..64 15725 75%
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65..80 44916 80%
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81..96 127815 93%
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97..112 34769 96%
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113..128 13314 98%
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129..144 8098 99%
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145..160 3355 99%
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161..176 1159 99%
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177..192 629 99%
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193..208 221 99%
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209..224 210 99%
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225..240 129 99%
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241..256 57 99%
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257..288 496 99%
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289..320 60 99%
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321..352 37 99%
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353..384 46 99%
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385..416 22 99%
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417..448 24 99%
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449..480 26 99%
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481..512 27 99%
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513..1024 471 99%
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1025..2048 389 99%
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2049..4096 182 99%
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4097..8192 74 99%
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8193..16384 34 99%
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16385..32768 17 99%
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32769..65536 5 99%
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65537..131073 3 100%
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This information is gathered to help design the new built-in
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backend for sqlite 2.0. Note in particular that 99% of all
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database entries have a combined key and data size of less than
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144 bytes. So if a leaf node in the new database is able to
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store 144 bytes of combined key and data, only 1% of the leaves
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will require overflow pages. Furthermore, note that no key
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is larger than 99 bytes, so if the key will never be on an
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overflow page.
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The average combined size of key+data is 48. Add in 16 bytes of
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overhead for a total of 64. That means that a 1K page will
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store (on average) about 16 entries.
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