Re: Why could different data in a table be processed with differentperformance?

On Mon, Sep 24, 2018 at 05:59:12PM -0700, Vladimir Ryabtsev wrote:
> > I *suspect* VACUUM FULL won't help, since (AIUI) it copies all "visible"
...
> I am going copy the slow range into a table nearby and see if it reproduces
> (I hope "INSERT INTO t2 SELECT * FROM t1 WHERE ..." will keep existing
> order of rows). Then I could try the same after CLUSTER.

If it does an index scan, I think that will badly fail to keep the same order
of heap TIDs - it'll be inserting rows in ID order rather than in (I guess)
reverse ID order.

Justin