Re: Clustered tables improves perfs ?
| От | Chris Browne |
|---|---|
| Тема | Re: Clustered tables improves perfs ? |
| Дата | |
| Msg-id | 608x7azkkq.fsf@dba2.int.libertyrms.com обсуждение исходный текст |
| Ответ на | Clustered tables improves perfs ? (Patrice Castet <pcastet@agematis.com>) |
| Список | pgsql-performance |
pcastet@agematis.com (Patrice Castet) writes: > I wonder if clustering a table improves perfs somehow ? > Any example/ideas about that ? > ref : http://www.postgresql.org/docs/8.2/interactive/sql-cluster.html Sometimes. 1. It compacts the table, which may be of value, particularly if the table is not seeing heavy UPDATE/DELETE traffic. VACUUM and VACUUM FULL do somewhat similar things; if you are using VACUUM frequently enough, this is not likely to have a material effect. 2. It transforms the contents of the table into some specified order, which will improve efficiency for any queries that use that specific ordering. -- output = reverse("moc.enworbbc" "@" "enworbbc") http://linuxdatabases.info/info/emacs.html "You can swear at the keyboard and it won't be offended. It was going to treat you badly anyway" -- Arthur Norman
В списке pgsql-performance по дате отправления: