On Tue, Dec 15, 2009 at 09:16:42AM -0800, Brian Aker wrote: > On Dec 14, 2009, at 9:27 PM, Stewart Smith wrote: > > > You can go from actions to SQL easily. > > > > You can also use the actions to simply write code that does the alter > > on non-sql systems (e.g. an applier that just uses Embedded InnoDB) > > SQL statements are interpreted by an engine. One engine may need to do a > rebuild of a full table, another may not. > > If an engine can just "add" a column, then the action for it may just be "add > column". If another engine needs to copy/rename/delete then it will have a > different set of actions. > > We need to be descriptive about the change, but the actual mechanics are up > to the individual engine.
I see it working as a 2 step process. step 1 is pass a list of changes to the engine and it returns a list of what it can't do. (this could then be used for EXPLAIN ALTER TABLE). If the list of what it can't do is not empty, we do a copying alter table. This would be applied the same way on a slave, as we have the original set of actions in the replication stream. -- Stewart Smith _______________________________________________ Mailing list: https://launchpad.net/~drizzle-discuss Post to : [email protected] Unsubscribe : https://launchpad.net/~drizzle-discuss More help : https://help.launchpad.net/ListHelp
