Movatterモバイル変換

If you have configurednon-persistent optimizer statistics (a non-default configuration),InnoDB computes indexcardinality values for a table the first time that table is accessed after startup, instead of storing such values in the table. This step can take significant time on systems that partition the data into many tables. Since this overhead only applies to the initial table open operation, to“warm up” a table for later use, access it immediately after startup by issuing a statement such asSELECT 1 FROMtbl_name LIMIT 1.

Optimizer statistics are persisted to disk by default, enabled by theinnodb_stats_persistent configuration option. For information about persistent optimizer statistics, seeSection 17.8.10.1, “Configuring Persistent Optimizer Statistics Parameters”.