Re: New FSM patch

Heikki Linnakangas <heikki.linnakangas@enterprisedb.com> writes:
> ... but we still haven't actually 
> established that the WAL-logging is causing the performance degradation 
> Zdenek observed.

Yeah, that's a good point.  I did some simple performance testing on
bulk inserts and updates, and found that while they indeed tended to be
WALInsertLock heavy, the FSM traffic seemed to be only a small part of
it.  Here are some xlog record type counts from a bulk update test:
686555 XLogInsert: rm 10 info 20    HEAP_UPDATE 89117 XLogInsert: rm 10 info 29    HEAP_UPDATE + bkp blk + removable
24526XLogInsert: rm 10 info 25    HEAP_UPDATE + bkp blk + removable  3199 XLogInsert: rm 10 info 2d    HEAP_UPDATE + 2
bkpblks + removable 27676 XLogInsert: rm 7 info 00    FSM_SET_AVAIL    35 XLogInsert: rm 7 info 09    SET_AVAIL + bkp
blk+ removable
 

So either by record count or by volume, the FSM traffic doesn't seem to
be much.  I wonder whether Zdenek knows what the xlog traffic is like
for his test in an unpatched database ...
        regards, tom lane