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Ticket UUID: 98d973b8f5a2ee195e69e949c880e08ac254f4f5
Title: Partial index gives incorrect query result
Status: Fixed Type: Code_Defect
Severity: Critical Priority: Immediate
Subsystem: Unknown Resolution: Fixed
Last Modified: 2014-08-27 17:41:38
Version Found In: 3.8.6
User Comments:
drh added on 2014-08-27 17:31:04:

The SELECT statement at the end of the following block of SQL outputs no rows, but it should output one row.

CREATE TABLE t1(a, b);
CREATE TABLE t2(c, d);
INSERT INTO t1 VALUES(1, 'xyz');
INSERT INTO t2 VALUES('abc', 'not xyz');
CREATE INDEX i2 ON t2(c) WHERE d='xyz'; 
SELECT * FROM (SELECT * FROM t1 WHERE a=1 AND b='xyz'), t2 WHERE c='abc';\

A correct result is obtained if the index created on the penultimate line is convert into a complete index or if the index is omitted entirely.

This bug appears to have been in the implementation of partial indexes from their introduction in SQLite version 3.8.0, 2013-08-26.