Heikki Linnakangas <heikki(at)enterprisedb(dot)com> writes:
> On every row, PageAddItem will scan all the line pointers on the target
> page, just to see that they're all in use, and create a new line
> pointer. That adds up, especially with narrow tuples like what I used in
> the test.
> Attached is a fix for that.
This has been proposed before, and rejected before. IIRC the previous
patch was quite a lot less invasive than this one (it didn't require
making special space on heap pages). I don't recall why it wasn't
accepted.
regards, tom lane