On Tue, Aug 4, 2009 at 5:37 PM, Mark Leith<[email protected]> wrote: >> Mark -- I agree with your 2 points, but I believe that >> multi-update/delete isn't necessary if subqueries work properly and >> efficiently. For example: DELETE FROM one_tbl WHERE stuff IN (....). >> >>> From what I see, multi-update and multi-delete are used to change >> >> information in *one* table, but the rows to change are determined by >> using more than one table. In that case, if/when subqueries work with >> proper efficiency, the real issue of "I want to easily change >> information in one table based on information in more than one table" >> will be solved -- appropriately and non-buggily. >> >> Have you found that multi-update/delete is used to actually change >> information in more than one table? All the implementations of *that >> usage* that I've seen in the wild have been instead of using foreign >> keys and cascading properly....... > > > > Yes I have - plenty. Foreign keys aren't in all storage engines.. ;)
Neither are transactions, and you mentioned that "2) It's extremely useful and convenient *not* to have to do this in a transaction" -- implying that you would do it in a transaction if you didn't have the multi-update/delete. What did you do before multi-update/delete was available? If you could do it in a transaction in MySQL, you can do it with foreign keys too (unless you were actually using BDB). I don't believe that multi-update/delete is implemented in MySQL in a way that's useful to avoid locking scenarios that would cause issues in the use cases that Drizzle is designed for. That's more of a feeling (I used the word "believe") than actual knowledge. > > Cheers, > -- > Mark Leith > MySQL Regional Support Manager, Americas > Sun Microsystems, Inc., http://www.sun.com/mysql/ > > > > > -- - Sheeri K. Cabral http://tinyurl.com/mysqlbook will take you to the Amazon.com page for my book, "MySQL Administrator's Bible". _______________________________________________ Mailing list: https://launchpad.net/~drizzle-discuss Post to : [email protected] Unsubscribe : https://launchpad.net/~drizzle-discuss More help : https://help.launchpad.net/ListHelp
