Re: updateable cursors & visibility

Neil Conway <neilc(at)samurai(dot)com> writes:
> - if the user updates a row X in the cursor, then rewinds the cursor and
> fetches X again, should they see the new X or the old X?

If it's considered an insensitive cursor, I'd think it should see the
old X. You would have a hard time making the code do otherwise in any
case --- the cursor's snapshot is frozen when the cursor is created.

> - if the user updates a row X in the cursor, and then a query within the
> cursor's transaction views X, should the query see new X or old X?

The subsequent query (if it's not going through the cursor) should and
will see the new X.

This should all be handled for you by the command-counter-based
visibility rules; I don't think you need to worry about it.

regards, tom lane