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17 check-ins related to "reuse-subqueries"

2018-12-31
20:39
Additional steps to help ensure that scalar subqueries are only evaluated once even if they are used in multiple places within the query. This fixes a performance regression reported on the mailing list and caused by check-in [531eca6104e41e43] which was a fix for ticket [787fa716be3a7f650c]. Think of this check-in as an improved fix for that ticket. (check-in: e1303193 user: drh tags: trunk)
20:13
Remove an optimization that can no longer occur, being superceded by the subquery-reuse optimization. Put an assert in place of the optimization to detect if the need for this optimization ever returns. (Closed-Leaf check-in: 4fcdc7a2 user: drh tags: reuse-subqueries)
18:30
Merge enhancements and bug fixes from trunk. (check-in: 9fb646f2 user: drh tags: reuse-subqueries)
17:58
Small changes to the OP_OpenEphemeral opcode to improve testability. (check-in: f856676c user: drh tags: trunk)
2018-12-28
21:40
Merge performance enhancements and other patches. (Leaf check-in: 44e1b55a user: drh tags: factor-out-scalar-subselect)
21:32
Merge performance enhancements from trunk. (check-in: 0f1b9ff9 user: drh tags: reuse-subqueries)
20:48
Faster allocation of new sqlite3_stmt objects. (check-in: 891f1f72 user: drh tags: trunk)
19:23
Merge patches and enhancements from trunk. (check-in: da53f3d3 user: drh tags: reuse-subqueries)
18:09
Fix another problem with loading the structure record from a corrupt fts5 database. (check-in: c4d44542 user: dan tags: trunk)
2018-12-26
15:04
Here is the beginnings of an effort to factor out the implementation of scalar subqueries to be implemented as subroutines at the end of the main body of bytecode, after the jump back to the OP_Init opcode. This is an incremental check-in that contains only preliminary changes. (check-in: 50e5f390 user: drh tags: factor-out-scalar-subselect)
2018-12-25
00:15
Increase the number of parameters to sqlite3WhereCodeOneLoopStart() to encourage the compiler to inline that routine within sqlite3WhereBegin(). This gives a performance improvement. (check-in: 3c2ad0e9 user: drh tags: reuse-subqueries)
2018-12-24
20:21
Improvements to EXPLAIN QUERY PLAN formatting. The MULTI-INDEX OR now shows a separate "INDEX" subtree for each index. SCALAR SUBQUERY entries provide a subquery number that is related back to the .selecttrace output. (check-in: 7153552b user: drh tags: reuse-subqueries)
14:30
Restore a line of code that was previously commented out for debugging. (check-in: e53781f5 user: drh tags: reuse-subqueries)
12:09
Do not generate subroutines for non-static SELECT and EXISTS expressions. Fix up some test cases to account for the minor changes in EXPLAIN QUERY PLAN output. (check-in: 06de44ec user: drh tags: reuse-subqueries)
11:55
Prevent the use of subroutines to implement the RHS of IN operators within CHECK constraints. (check-in: 6b24d3fb user: drh tags: reuse-subqueries)
02:34
Experimental code that tries to put the computation of subqueries inside a subroutine, and reuse that subroutine if the same subquery is evaluated more than once. Current code does not work for CHECK constraints. (check-in: 6c44838a user: drh tags: reuse-subqueries)
2018-12-23
21:27
Split the code generation for the RHS of IN operators and for SELECT and EXISTS expressions into two separate subroutines, because there is now little commonality between those to functions. This is intended to help make the code easier to read and maintain. (check-in: 2b6494b1 user: drh tags: trunk)