Andres Freund <and...@anarazel.de> writes: > On 2016-08-23 17:22:03 -0400, Tom Lane wrote: >> I can't immediately think of a reason for this. In everyday >> updates you could theorize about effects like autovacuum >> asynchonously updating the FSM, but surely the FSM should have no >> impact on where COPY puts stuff when loading into an empty table.
> It seems possible that a larger row didn't fit on a page anymore, then > later when a new page was is needed for a smaller row, the earlier page > is found again. Due to RelationGetBufferForTuple() updating the fsm > when an old target buffer is present: Ah. That matches the symptoms --- small groups of rows are getting relocated, seems like. And there's definitely a wide range of row lengths in this data. It's interesting that nobody has complained about this behavior. Maybe the old fogies are all gone ... regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers