Hi! On Mon, Dec 1, 2008 at 9:54 PM, Brian Aker <[EMAIL PROTECTED]> wrote: > Hi! > > It crosses my mind several times a day that if we required primary keys on > tables that replication with be far less of a hack (and work quite a bit > better). Why? Because we could then target update/delete on other machines > with primary keys and just execute directly on those keys. > > Without primary keys? You have to map the rows and do a LIMIT 1 on the > queries. Really slow...
Maybe I'm off by a mile but I'll give it a go. If I understand correctly, you are saying that if you would be sure that you can always identify a single row in any table, replication would be much simpler. Although I agree that a PRIMARY KEY would satisfy that condition, I feel I should point out that a PRIMARY KEY is a logical construct whereas all you really need is some physical way to identify a row. So, if some kind of engine is known to have some device that always allows physical identification (which may or may not be accessible to the end-user from the SQL layer), then you could go by that device, regardless of the existence of a PRIMARY KEY in the logical model. I am not saying this just to nitpick - If an engine has such a built-in row-identifier it may be more efficient than the logical primary key (especially if that happens to be a natural key). So, my proposal would be to allow engines to advertise any internal row-identifiers (and probably, the methods to look up a row using such an identifier) that they may maintain to the API (should this be a suitable key for replication). Of course, you can still demand that a logical primary key be present in case an engine does not support such a feature. regards, Roland > > Cheers, > -Brian > > -- > _______________________________________________________ > Brian "Krow" Aker, brian at tangent.org > Seattle, Washington > http://krow.net/ <-- Me > http://tangent.org/ <-- Software > _______________________________________________________ > You can't grep a dead tree. > > > > > _______________________________________________ > Mailing list: https://launchpad.net/~drizzle-discuss > Post to : [email protected] > Unsubscribe : https://launchpad.net/~drizzle-discuss > More help : https://help.launchpad.net/ListHelp > -- Roland Bouman http://rpbouman.blogspot.com/ _______________________________________________ Mailing list: https://launchpad.net/~drizzle-discuss Post to : [email protected] Unsubscribe : https://launchpad.net/~drizzle-discuss More help : https://help.launchpad.net/ListHelp
