Commit Graph

3 Commits

Author SHA1 Message Date
drh 5822d6feb2 Fix test cases for the new EXPLAIN QUERY PLAN format. Add the
wherecosttest tool.  Other fixes to logarithm cost.

FossilOrigin-Name: aa580e368e3c398b8377b80342dfdd906324c248
2013-06-10 23:30:09 +00:00
drh 3f4d1d1b02 Attempt to use a covering index even on a full table scan, under the theory
that the index will be smaller and require less disk I/O and thus be faster.

FossilOrigin-Name: cfaa7bc12847a7006ccc93815f2395ad5259744a
2012-09-15 18:45:54 +00:00
dan 6a36f43586 Do not consider a DISTINCT clause redundant unless a subset of the result-set is collectively subject to a UNIQUE constraint and it can be guaranteed that all columns of the subset are NOT NULL (either due to NOT NULL constraints WHERE clause terms). Fix for [385a5b56b9].
FossilOrigin-Name: 7b8548b1872cc1225355ba8311e93dd08d6526e2
2012-04-20 16:59:24 +00:00