Hello. I've found strange behavior of my pg installation (tested both 8.4 and 9.0 - they behave same) on FreeBSD platform. In short - when some table have PK on bigint field - COPY to that table from file becomes slower and slower as table grows. When table reaches ~5GB - COPY of 100k records may take up to 20 mins. I've experimented with all params in configs, moved indexes to separate hdd etc - nothing made any improvement. However, once I'm dropping 64 bit PK - COPY of 100k records passes in seconds. Interesting thing - same table has other indexes, including composite ones, but none of them include bigint fields, that's why I reached decision that bug connected with indexes on bigint fields only. In terms of IO picture is following: after copy started gstat shows 100% load on index partition (as I mentioned above - I've tried separate hdd to keep index tablespace), large queue (over 2k elements), and constant slow write on speed of ~2MB\s. Hdd becomes completely unresponsive, even ls on empty folder hangs for minute or so. To avoid thoughts like "your hdd is slow, you haven't tuned postgresql.conf etc" - all slowness dissapears with drop of bigint PK, same time other indexes on same table remain alive. And yes - I've tried drop PK \ recreate PK, vacuum full analyze and all other things - nothing helped, only drop helps. Is this known and expected behavior? -- Ayrapetyan Robert, Comodo Anti-Malware Data Processing Analysis and Management System (CAMDPAMS) http://repo-qa.camdpams.odessa.office.comodo.net/mediawiki/index.php -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
