On an environment with more thatn 500000 tables, the mysqldump is slow on dumping separate tables.
mysqldump uses the traditional queries like
instead of querying information_schema.tables .
takes 0.0011s, while
takes about 10 seconds. This makes the dumps unnecessary slow.
mysqldump could use the information_schema here (after checking the server version), or the server could detect LIKE-Patterns that can only expand to exactly one table name (because there are no wildcards) and use a more intelligent algorithm internally, e.g. use the implementation of information_schema.tables .