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12 check-ins related to "enhanced-stat1"
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2024-01-01
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| 15:49 | Improved defenses against deliberately corrupted sqlite_stat1 tables. (Closed-Leaf check-in: ee34db31 user: drh tags: enhanced-stat1) | |
| 15:35 | Fix a harmless compiler warning. (check-in: b5aa1aea user: drh tags: enhanced-stat1) | |
| 14:13 | Omit the uneven=N argument in sqlite_stat1 and replace it with var=N1,N2,... so that the variation in each column is reported separately. Omit the "slow" argument from sqlite_stat1, computing that flag internally. PRAGMA stats is enhanced with a new column "est" that shows the aiRowLogEst array for each index after it has been modified by "var=..." and also the "slow" flag. (check-in: 4a8fc173 user: drh tags: enhanced-stat1) | |
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2023-12-31
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| 20:04 | Better comments. Slight tuning of parameters. (check-in: 1cc32ecc user: drh tags: enhanced-stat1) | |
| 12:38 | Ensure that all elements of aiRowLogEst[] have been initialized even if the stat entry is truncated. (check-in: c216921b user: drh tags: enhanced-stat1) | |
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2023-12-30
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| 22:00 | In sqlite_stat1, revert the number of rows to the average, not adjusted for the maximum. Instead add "uneven=NNN" where NNN is a multiplier to apply to the average to get the maximum. "uneven" is only reported if NNN is 10 or more. Also add the "slow" argument is the maximum number of rows reported by a full equality match is so large that a table scan seems likely to be faster. (check-in: 41773fa7 user: drh tags: enhanced-stat1) | |
| 15:07 | Omit the "noquery" argument in sqlite_stat1. Instead, add the "uneven" argument for indexes that have an uneven distribution of values. Modify the query planner to avoid doing equality look-ups on uneven indexes. (check-in: 0ec4b880 user: drh tags: enhanced-stat1) | |
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2023-12-29
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| 21:07 | Revise the "noquery" decision algorithm again. The index now must select more than 150 rows on average, and the number of rows select must be enough that it seems faster to do a full scan of the associated table. (check-in: f516ef80 user: drh tags: enhanced-stat1) | |
| 20:31 | Fix an issue in the "noquery" decision in the previous check-in. Also add comments explaining the algorithm. (check-in: 6aaa65ad user: drh tags: enhanced-stat1) | |
| 20:08 | Add the "noquery" argument as an option for the stat column of sqlite_stat1. If set, then the index will not be used to optimize a query. Enhance ANALYZE to set that argument on very low selectivity indexes. (check-in: e514d3fa user: drh tags: enhanced-stat1) | |
| 19:03 | Attempt to improve the ANALYZE command so that it does a better job of detecting lopsided indexes and makes appropriate changes to the sqlite_stat1 table. (check-in: 4b70b946 user: drh tags: enhanced-stat1) | |
| 04:29 | Minor doc touchup in the JS bits. (check-in: 8d2120c3 user: stephan tags: trunk) | |