Spracherkennung für: .test vermutete Sprache: SQL {SQL[184] ABAP[84] Masm[76]} [Methode: maximale Elemente, drei Dimensionen]
--echo #
--echo # MDEV-36169: LooseScan optimization picks invalid plan
--echo #
--source include/have_innodb.inc
CREATE TABLE t1 (a INTEGER NOT NULL, b INT, UNIQUE KEY (a)) engine=InnoDB;
CREATE TABLE t2 (a INTEGER NOT NULL, KEY (a));
CREATE TABLE t3 (a INTEGER NOT NULL, b INT, KEY (a));
INSERT INTO t1 VALUES (1,10), (2,20), (3,30), (4,40);
INSERT INTO t2 VALUES (2), (2), (3), (3), (4), (5);
INSERT INTO t3 VALUES (10,3), (15,3), (20,4), (30,5);
--echo # Must not be: t3, t3(LooseScan), t1
EXPLAIN EXTENDED
SELECT * FROM t1
WHERE
t1.a IN (SELECT /*+ SEMIJOIN(LOOSESCAN) */ a FROM t2) AND
t1.b IN (SELECT /*+ SEMIJOIN(LOOSESCAN) */ a FROM t3);
DROP TABLE t1,t2,t3;
[Dauer der Verarbeitung: 0.11 Sekunden, vorverarbeitet 2026-10-08]