"Christopher Kings-Lynne" <[EMAIL PROTECTED]> writes: >> Why would there be any speed advantage?
> Is it not faster to add it when all the data is there, rather than > evaluating it as each row is inserted, like indexes? I don't see why. There are good algorithmic reasons why bulk-loading an index is faster than retail insertions --- mainly that btree goes out of its way to make it so, with a special code path. But I see no reason why checking a constraint expression is going to be any faster as a post-pass than when done while loading the data. If anything, I'd guess it to be slower because you have to re-read the table. regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 3: if posting/reading through Usenet, please send an appropriate subscribe-nomail command to [EMAIL PROTECTED] so that your message can get through to the mailing list cleanly