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2018-07-27
20:37
The WHERE-clause constant propagation optimization attempts to use transitive laws to replace column values with constants in the WHERE clause in order to help to query planner make more aggressive optimizations. check-in: f4229707ac user: drh tags: trunk
20:01
Reduce the performance cost of the constant propagation optimization to less than 200,000 cycles. Closed-Leaf check-in: 865249de68 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: a5f86f49b7 user: drh tags: propagate-const-opt
18:12
Faster implementation of sqlite3IsBinary(). check-in: be05d0db09 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: 598d608359 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: 82c67efb72 user: drh tags: propagate-const-opt
2018-07-26
23:54
Add a test case demonstrating the collation problem with constant propagation. check-in: 50add839fd 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: 57eb2abd5b user: drh tags: propagate-const-opt
21:16
Initial implementation of the WHERE-clause constant propagation optimization. check-in: 2fb82ad8eb user: drh tags: propagate-const-opt
2018-07-25
15:25
Fix a buffer overread in fts5. check-in: 0e3de8abbb user: dan tags: trunk