Extended mysqldump

Backup locks support

When used together with the –single-transaction option, the lock-for-backup option makes mysqldump issue LOCK TABLES FOR BACKUP before starting the dump operation to prevent unsafe statements that would normally result in an inconsistent backup.

More information can be found in Backup Locks.

Compressed columns support

mysqldump supports the Compressed columns with dictionaries feature.

More information can be found in Compressed columns with dictionaries.

InnoDB secondary keys and --innodb-optimize-keys

For InnoDB tables, --innodb-optimize-keys omits secondary keys (and related constraints) from the initial CREATE TABLE in the dump and adds them in a follow-up ALTER TABLE after the data is loaded. That pattern works well when the target server can build those indexes using expanded fast index creation. See that page for limitations (foreign keys, partitioned tables, AUTO_INCREMENT, implicit primary keys, and others) and for the expand_fast_index_creation variable.

Taking backup by descending primary key order

–order-by-primary-desc tells mysqldump to take the backup by descending primary key order (PRIMARY KEY DESC) which can be useful if the storage engine is using the reverse order column for a primary key.

RocksDB support

mysqldump detects when MyRocks is installed and available. If there is a session variable named rocksdb_skip_fill_cache, mysqldump sets the variable to 1.

mysqldump automatically enables rocksdb_bulk_load if the the target server supports the variable.