Overview
Artifact ID: | a444fa6b9bb777649d9ce5698f3fad0eb800551c |
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Ticket: | 4c86b126f22ad548fee0125337bdc9366912d9ac
Incorrect query result with SQLITE_ENABLE_STAT4 |
User & Date: | drh 2014-02-10 22:46:11 |
Changes
- foundin changed to: "3.8.3"
- icomment:
When SQLite is compiled using SQLITE_ENABLE_STAT3 or SQLITE_ENABLE_STAT4, it gets the wrong answer for the first of the two queries below: <blockquote><verbatim> CREATE TABLE nodes( local_relpath TEXT PRIMARY KEY, moved_to TEXT ); INSERT INTO nodes VALUES('A',NULL); INSERT INTO nodes VALUES('A/B',NULL); INSERT INTO nodes VALUES('',NULL); INSERT INTO nodes VALUES('A/B/C-move',NULL); INSERT INTO nodes VALUES('A/B/C','A/B/C-move'); INSERT INTO nodes VALUES('A/B-move',NULL); INSERT INTO nodes VALUES('A/B-move/C-move',NULL); INSERT INTO nodes VALUES('A/B-move/C','x'); SELECT local_relpath, moved_to FROM nodes WHERE (local_relpath = 'A/B' OR ((local_relpath > 'A/B/') AND (local_relpath < 'A/B0'))) AND moved_to IS NOT NULL; .print ------------------------------------------------ SELECT local_relpath, moved_to FROM nodes WHERE (+local_relpath = 'A/B' OR ((local_relpath > 'A/B/') AND (local_relpath < 'A/B0'))) AND moved_to IS NOT NULL; </verbatim></blockquote> The bug appears to have been inserted into trunk with the STAT4 changes of check-in [a32af0abe5fa6d] which occurred just after the release of 3.8.0. The bug first appeared in 3.8.1. Note that it is not necessary to run ANALYZE or to have sqlite_stat3 or sqlite_stat4 tables in the database. The only requirement is to compile with SQLITE_ENABLE_STAT3 or SQLITE_ENABLE_STAT4. The extra unary "+" operator in the second queries disable the OR optimization and enables the second query to get the correct answer regardless. This bug was discovered in the wild by the SVN developers.
- login: "drh"
- mimetype: "text/x-fossil-wiki"
- severity changed to: "Critical"
- status changed to: "Open"
- title changed to: "Incorrect query result with SQLITE_ENABLE_STAT4"
- type changed to: "Code_Defect"