mysql hint

5.7

 

SELECT /*+ NO_SEMIJOIN(@subq1 FIRSTMATCH, LOOSESCAN) */ * FROM t2

WHERE t2.a IN (SELECT /*+ QB_NAME(subq1) */ a FROM t3);

 

SELECT /*+ SEMIJOIN(@subq1 MATERIALIZATION, DUPSWEEDOUT) */ * FROM t2

WHERE t2.a IN (SELECT /*+ QB_NAME(subq1) */ a FROM t3);

 

SELECT id, a IN (SELECT /*+ SUBQUERY(MATERIALIZATION) */ a FROM t1) FROM t2;

SELECT * FROM t2 WHERE t2.a IN (SELECT /*+ SUBQUERY(INTOEXISTS) */ a FROM t1);

 

SELECT /*+ MAX_EXECUTION_TIME(1000) */ * FROM t1 INNER JOIN t2 WHERE ...

 

SELECT /*+ QB_NAME(qb1) MRR(@qb1 t1) BKA(@qb2) NO_MRR(@qb3t1 idx1, id2) */ ...

FROM (SELECT /*+ QB_NAME(qb2) */ ... FROM (SELECT /*+ QB_NAME(qb3) */ ... FROM ...)) ...

 

SELECT /*+ BKA(@`my hint name`) */ ... FROM (SELECT /*+ QB_NAME(`my hint name`) */ ...) ...

 

SELECT /*+ BKA(@"my hint name") */ ... FROM (SELECT /*+ QB_NAME("my hint name") */ ...) ...