8.5.5 Bulk Data Loading for InnoDB Tables

When importing data into InnoDB, turn off autocommit mode, because it performs a log flush to disk for every insert. To disable autocommit during your import operation, surround it with SET autocommit and COMMIT statements:

The mysqldump option --opt creates dump files that are fast to import into an InnoDB table, even without wrapping them with the SET autocommit and COMMIT statements.

If you have UNIQUE constraints on secondary keys, you can speed up table imports by temporarily turning off the uniqueness checks during the import session:

For big tables, this saves a lot of disk I/O because InnoDB can use its change buffer to write secondary index records in a batch. Be certain that the data contains no duplicate keys.

If you have FOREIGN KEY constraints in your tables, you can speed up table imports by turning off the foreign key checks for the duration of the import session:

For big tables, this can save a lot of disk I/O.

Use the multiple-row INSERT syntax to reduce communication overhead between the client and the server if you need to insert many rows:

This tip is valid for inserts into any table, not just InnoDB tables.

When doing bulk inserts into tables with auto-increment columns, set innodb_autoinc_lock_mode to 2 (interleaved) instead of 1 (consecutive). See Section 15.6.1.4, “AUTO_INCREMENT Handling in InnoDB” for details.

When performing bulk inserts, it is faster to insert rows in PRIMARY KEY order. InnoDB tables use a clustered index, which makes it relatively fast to use data in the order of the PRIMARY KEY. Performing bulk inserts in PRIMARY KEY order is particularly important for tables that do not fit entirely within the buffer pool.

For optimal performance when loading data into an InnoDB FULLTEXT index, follow this set of steps: