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8 check-ins tagged with "propagate-const-opt"

2018-07-27
20:01
Reduce the performance cost of the constant propagation optimization to less than 200,000 cycles. (Closed-Leaf check-in: 865249de user: drh tags: propagate-const-opt)
18:19
Performance improvement to sqlite3ExprCollSeq(). With this change, the performance of speed-check.sh is within 400,000 cycles of trunk. (check-in: a5f86f49 user: drh tags: propagate-const-opt)
18:12
Faster implementation of sqlite3IsBinary(). (check-in: be05d0db user: drh tags: propagate-const-opt)
17:51
Only run the constant propagation optimization on joins since that is the only scenario where it is useful. This saves prepare time for the common case of a simple query. (check-in: 598d6083 user: drh tags: propagate-const-opt)
16:57
Constant propagation is now restricted to just the WHERE clause. The mechanism is changed to take affinity and collation into account. This seems to give correct answers. But the search for constant propagation costs 4 million cycles in the speed test. (check-in: 82c67efb user: drh tags: propagate-const-opt)
2018-07-26
23:54
Add a test case demonstrating the collation problem with constant propagation. (check-in: 50add839 user: drh tags: propagate-const-opt)
23:47
Generalize the constant propagation optimization so that it applies on every WHERE close, not just those that contain a subquery. This then demonstrates that the current implementation is inadequate since it does not take into account collating sequences. (check-in: 57eb2abd user: drh tags: propagate-const-opt)
21:16
Initial implementation of the WHERE-clause constant propagation optimization. (check-in: 2fb82ad8 user: drh tags: propagate-const-opt)