Optimizer Hints Hint Name Description Applicable Scopes HASH_JOIN ,  NO_HASH_JOIN Affects Hash Join optimization (MySQL 8.0.18 only Query block, table INDEX ,  NO_INDEX Acts as the combination of JOIN_INDEX ,  GROUP_INDEX , and  ORDER_INDEX , or as the combination of  NO_JOIN_INDEX , NO_GROUP_INDEX , and NO_ORDER_INDEX  (Added in MySQL 8.0.20) Index INDEX_MERGE , NO_INDEX_MERGE Affects Index Merge optimization Table, index JOIN_FIXED_ORDER Use table order specified in  FROM clause for join order Query block JOIN_INDEX ,  NO_JOIN_INDEX Use or ignore the specified index or indexes for any access method (Added in MySQL 8.0.20) Index JOIN_ORDER Use table order specified in hint for join order Query block JOIN_PREFIX Use table order specified in hint for first tables of join order Query block JOIN_SUFFIX Use table order specified in hint for last tables of join order Query block MAX_EXECUTION_TIME Limits statement execution time Global MERGE ,  NO_MERGE Affects derived table/view merging into outer query block Table MRR ,  NO_MRR Affects Multi-Range Read optimization Table, index NO_ICP Affects Index Condition Pushdown optimization Table, index NO_RANGE_OPTIMIZATION Affects range optimization Table, index ORDER_INDEX , NO_ORDER_INDEX Use or ignore the specified index or indexes for sorting rows (Added in MySQL 8.0.20) Index QB_NAME Assigns name to query block Query block RESOURCE_GROUP Set resource group during statement execution Global SEMIJOIN ,  NO_SEMIJOIN Affects semijoin strategies; beginning with MySQL 8.0.17, this also applies to antijoins Query block SKIP_SCAN ,  NO_SKIP_SCAN Affects Skip Scan optimization Table, index SET_VAR Set variable during statement execution Global SUBQUERY Affects materialization,  IN - to- EXISTS  subquery stratgies Query block 1793