Tom Lane wrote: > Heikki Linnakangas <[EMAIL PROTECTED]> writes: >> Yes, re-fetching row you just deleted is supposed to raise an error. >> That doesn't seem very hard to implement. If an UPDATE/DELETE CURRENT OF >> doesn't find the tuple to update/delete, raise an error. > > Uh, no, the error would have to come from FETCH RELATIVE 0, and there's > a problem because no single piece of the code has all the facts needed > to know that an error should be thrown. I don't currently see any > non-klugy way to detect that.
No, FETCH RELATIVE 0 is supposed to be a no-op. If the cursor is positioned "before a row", it's still positioned before a row after FETCH RELATIVE 0. That's the way I read the spec, anyway. But if it's not easy to do, I'm OK with leaving that out. > It might make sense to go with Simon's suggestion to just forbid > non-forwards fetch from a FOR UPDATE cursor (assuming that we agree he's > read the spec correctly to disallow that). I don't see that in the spec. It does say that "if <updatability clause> is not specified, then if either INSENSITIVE, SCROLL, or ORDER BY is specified, or if QE is not a simply updatable table, then an <updatability clause> of READ ONLY is implicit". It also says "If an <updatability clause> of FOR UPDATE with or without a <column name list> is specified, then INSENSITIVE shall not be specified". But I don't see anything forbidding SCROLL FOR UPDATE combination. -- Heikki Linnakangas EnterpriseDB http://www.enterprisedb.com ---------------------------(end of broadcast)--------------------------- TIP 6: explain analyze is your friend