On Wed, 1 Oct 2003, Tom Lane wrote: > Stephan Szabo <[EMAIL PROTECTED]> writes: > > On Tue, 30 Sep 2003, Tom Lane wrote: > >> I think I can implement it and it will act as stated in my proposal. > >> Whether people like the proposed behavior is the big question in my > >> mind. > > > I think it's more reasonable than the current behavior or any of > > the others we've hit along the way, and we have to pretty much choose > > now if we want to change it for 7.4. > > I've committed the attached patch. One thing I wanted to double-check > with you is that the SELECT FOR UPDATES done in the noaction cases are > being correctly handled. I think it is correct to do them with the > current snapshot rather than the start-of-transaction snap; do you > agree? Also, I did not propagate the crosscheck support into
I think the ones in the main functions need to be current snapshot. I think the one in ri_Check_Pk_Match doesn't need to be. That's there to see if this same transaction has inserted a new row with the old value of the updated/deleted pk row and the serializable snapshot should be fine. Any conflicting attempts from another transaction should be waiting on our completion due to the unique index I think. > heap_mark4update, meaning that these SELECT FOR UPDATEs won't complain > if they find a row that was inserted later than the start of the > serializable transaction. I'm not totally sure if they should or not; > what do you think? Well, I think that not doing so would only change the error from a serialization error to a matching row exists error. It might be a bit surprising if you've just done a select yourself and seen that there were no matching rows, but I'm not sure that it's a big deal as long as it errors as appropriate. ---------------------------(end of broadcast)--------------------------- TIP 1: subscribe and unsubscribe commands go to [EMAIL PROTECTED]
