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22 check-ins related to "skip-ahead-distinct"

2017-04-15
11:53
In the skip-ahead-distinct optimization, fix a bug in the logic that determines when to invoke the optimization based on sqlite_stat1 statistics. (check-in: 89f9e436 user: drh tags: trunk)
2017-04-14
22:41
Fix to the decision logic for when to use the skip-ahead-distinct optimization. (Closed-Leaf check-in: e50fd489 user: drh tags: skip-ahead-distinct)
17:30
When doing a DISTINCT query using an index, try to use the index to skip ahead to the next distinct element, rather than doing a full scan of the index. (This is the "skip-ahead-distinct" optimization.) (check-in: f489b5bb user: drh tags: trunk)
00:45
Fix a couple of unreachable branches. (check-in: 1aa0ea8d user: drh tags: skip-ahead-distinct)
2017-04-13
21:29
Fix the skip-ahead-distinct optimization so that it works with indexes that have repeated columns with different collating sequences. (check-in: ce1e2b88 user: drh tags: skip-ahead-distinct)
19:48
Simplification of the skip-ahead-distinct logic. There is still an issue with handling COLLATE. (check-in: 57c5173b user: drh tags: skip-ahead-distinct)
18:33
New test cases and minor fixes for the optimization on this branch. (check-in: 70ac9ea1 user: dan tags: skip-ahead-distinct)
13:01
Only use the skip-ahead-distinct optimization if the index has been analyzed and we know that a skip-head is likely to skip over at least 11 rows. The magic number 11 was determined by experimentation. (check-in: 0cf16dec user: drh tags: skip-ahead-distinct)
01:19
Forward port the skip-ahead-distinct branch which was abandoned for some reason that I do not recall. This port should have been achived by a merge of trunk into the previous head of skip-ahead-distinct, but that did not work. So I had to manually "rebase" the changes. (check-in: 132339a1 user: drh tags: skip-ahead-distinct)
00:12
Fix a regression caused by the fix for ticket [6c9b5514077fed34551f98e64c09a1] - control characters allowed in JSON. (check-in: 8e7b6118 user: drh tags: trunk)
2016-04-21
15:44
Merge the latest changes from trunk. (Closed-Leaf check-in: 8183fa68 user: drh tags: skip-ahead-distinct)
02:27
Add the SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION method for enabling sqlite3_load_extension() while leaving the load_extension() SQL function disabled. (check-in: c4f165c4 user: drh tags: trunk)
2016-04-15
22:03
Add the SQLITE_SkipAhead optimization setting (check-in: 87703b76 user: drh tags: skip-ahead-distinct)
16:27
Skip-ahead is now just an optimization. If it gets confused, it falls back to an incremental scan with redundancy elimination. (check-in: 6fac0b92 user: drh tags: skip-ahead-distinct)
16:17
Skip-ahead does not always work. So we still have to check for redundancy. (check-in: db5a2364 user: drh tags: skip-ahead-distinct)
15:54
Fixes to the skip-ahead distinct logic. More issues remain. (check-in: 45a70b2b user: drh tags: skip-ahead-distinct)
15:06
Merge enhancements from trunk, especially the ".eqp full" enhancement to the command-line shell. (check-in: 491f0dbd user: drh tags: skip-ahead-distinct)
15:03
CLI enhancement: Add the ".eqp full" option, that shows both the EXPLAIN QUERY PLAN and the EXPLAIN output for each command run. Also disable any ".wheretrace" and ".selecttrace" when showing EQP output. (check-in: 3e217d62 user: drh tags: trunk)
14:13
Several new test cases that cause failures. (check-in: 0379f2cf user: drh tags: skip-ahead-distinct)
13:24
Fixed crash bugs. Still sometimes gets the wrong answers. (check-in: 2afcb2c7 user: drh tags: skip-ahead-distinct)
01:55
Progress toward getting DISTINCT to use a seek to advance to the next distinct row, when driven by an appropriate index. (check-in: 9e14aa14 user: drh tags: skip-ahead-distinct)
2016-04-14
19:29
Work toward improving analysis and code generation for DISTINCT and aggregate queries. (Leaf check-in: 129083bd user: drh tags: better-distinct-agg)