On Wed, Nov 25, 2009 at 17:42, Jay Pipes <[email protected]> wrote: > Brian Aker wrote: >> >> Hi! >> >> I was just about to guy RENAME TABLE and then realized that it has one >> difference with ALTER TABLE... it doesn't do TEMPORARY TABLES. >> So if I change it, it now does temporary tables... which makes me >> wonder... >> >> Can this just go away? If someone really wants this they can write an >> alias in the client for it. > > As a number of folks have already mentioned, the perceived[1] ability to do > atomic renames *of multiple tables in a single statement* is the main > benefit of RENAME TABLE, and this is a nice feature. > > So, I would say, keep it. > > Cheers, > > Jay > > [1] I'm still questioning whether this behaviour (of renaming multiple > tables) is actually atomic after looking through the code. What the code > ensures is that if one of the tables is not renamed properly, all the tables > will have their original names restored. However, because there is no > transactional state to this SQL statement, if the power cuts out halfway > through the operation to rename a list of tables, I see nothing in the code > which would recover the original table names on a restart of the server. So, > it's kind of a "phony" atomicity since it is not guaranteed to be consistent > or durable.
Yeah, you're right. This is probably because if a solution for actual transactional-table-renaming existed, it'd likely just be used for all other DDL statements, since it'd involve something like the write-ahead log. Transactional DDL statements exist in a number of other relational RDBMS (e.x., Postgre, SQL Server, Oracle, Sybase). The implicit commits in MySQL are very ugly, so if we're addressing the RENAME TABLE issue, I think this deserves discussion. -- Darius Jahandarie _______________________________________________ Mailing list: https://launchpad.net/~drizzle-discuss Post to : [email protected] Unsubscribe : https://launchpad.net/~drizzle-discuss More help : https://help.launchpad.net/ListHelp
