I really thought this would have caused some interest, since - this item is in the TODO list - the improvement for CLUSTER in some scenarios is 800%, and maybe more (if I didn't do anything wrong, of course...)
Could at least the message: http://archives.postgresql.org/pgsql-hackers/2010-02/msg00766.php be added to the TODO page, under "Improve CLUSTER performance by sorting to reduce random I/O" ? It would be sad if the patch got lost... Leonardo > Attached the updated patch (should solve a bug) and a script. > The sql scripts generates a 2M rows table ("orig"); then the > table is copied and the copy clustered using seq + sort (since > "set enable_seqscan=false;"). > Then the table "orig" is copied again, and the copy clustered > using regular index scan (set enable_indexscan=true; set > enable_seqscan=false). > Then the same thing is done on a 5M rows table, and on a 10M > rows table. > > On my system (Sol10 on a dual Opteron 2.8) single disc: > > > 2M: seq+sort 11secs; regular index scan: 33secs > 5M: seq+sort 39secs; regular index scan: 105secs > 10M:seq+sort 83secs; regular index scan: 646secs > > > Maybe someone could suggest a better/different test? > > > Leonardo -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers
