ITAGAKI Takahiro <[EMAIL PROTECTED]> writes: > Tom Lane <[EMAIL PROTECTED]> wrote: >> The problem is that we've traded splitting a page every few hundred >> inserts for doing a PageIndexMultiDelete, and emitting an extra WAL >> record, on *every* insert. This is not good.
> I suspect PageIndexMultiDelete() consumes CPU. That's part of the problem, but only part: the extra WAL record is expensive too. > If there are one or two > dead tuples, PageIndexTupleDelete() is called and memmove(4KB average) > and adjustment of the linepointer-offsets are performed everytime. > I think this is a heavy operation. But if the size of most upper index > entry is same with the dead tuple, we can only move the upper to the hole > and avoid to modify all tuples. Is this change acceptable? I'm inclined to think that this is too special-purpose to be a good solution. It will help pgbench because that test uses only integer keys, but it won't help for any variable-width datatype. In any case we'd still have the WAL overhead... regards, tom lane ---------------------------(end of broadcast)--------------------------- TIP 1: 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