Passes hints from the server to the storage engine.

This is the extra method.

extra() is called whenever the server wishes to send a hint to the storage engine. The MyISAM engine implements the most hints. ha_innodb.cc has the most exhaustive list of these hints.

There are no return values.

Most storage engines will simply return 0.

{ return 0; }

By default your storage engine can opt to implement none of the hints.

{ return 0; }