I have a table in MySQL that I need to rebuild for performance/storage reasons. Is it possible to use pt-online-schema-change with no changes for this purpose or is a change always required? If the former, can I specify this in Liquibase XML?
CodePudding user response：
Yes, I've done this frequently to defragment and recover disk space on a table after a lot of updates or deletes. Any no-op alteration would work the same with pt-online-schema-change, but I use the option --alter=FORCE because it's mnemonic for ALTER TABLE <name> FORCE which would be a no-op table restructure if one were not using pt-online-schema-change.
I'm not familiar with Liquibase enough to know how to use it to run a pt-online-schema-change task.
CodePudding user response：
InnoDB tables rarely need OPTIMIZE TABLE.
Big DELETEs should be performed in one of several more optimal ways. Some other ways inherently lead to defragmenting as a side effect.