Index Hints¶

MemSQL supports the following index hint syntax:

tbl_name [index_hint]

index_hint:
    USE {INDEX | KEY} (index_list)
  | IGNORE {INDEX | KEY} (index_list)
  | FORCE {INDEX | KEY} (index_list)

index_list:
    index_name [, index_name] ...

USE and FORCE hints force the use of one of the specified indexes to run the query. In MemSQL, there is no difference between a USE and FORCE hint. IGNORE hints disallow the specified indexes from being used to run the query.

The EXPLAIN <query> statement can be used to show which indexes the query considers and which one it will actually use.