SQLite

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.