On 21 Sep 2009, at 5:38pm, Brad House wrote: > It could probably benefit a large number of integrations to > have finer grained locking even if it could not be implemented for all > integration types.
It makes the system a great deal slower, since you need to keep checking all the levels of lock you have implemented. For instance, UPDATE props SET colour='black',condition='poor' WHERE description='fake sword' needs to check for locks on the file, the record, and three fields. That's five operations before you can even start to modify the data. Could easily double the amount of time it takes to perform the update. And if you implement column locks there are even more. And implementing fine-grain locks leads to lock-contention: if someone locks a record and you try to lock a field in that record, what should happen ? Now before trying to modify data and having locks interfere, you're trying to modify locks and having lock-interaction interfere. Simon. _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
