Re: CLUSTER command
От | Jean-Luc Lachance |
---|---|
Тема | Re: CLUSTER command |
Дата | |
Msg-id | 3DF90248.9BAF931C@nsd.ca обсуждение исходный текст |
Ответ на | CLUSTER command (Jean-Luc Lachance <jllachan@nsd.ca>) |
Список | pgsql-performance |
Oh, and something else, I think the syntax should be: Cluster <table> on <attribute> Maybe inheritance can be use here. The problem is creating the new "table" when a new key is detected. I know, I can use rules, but the optimiser is not aware of the clustering. Enough from me for now. What do you think? JLL Jean-Luc Lachance wrote: > > Hi all, > > I just read about the cluster command and was a little (very) > disapointed. > Clustered tables do not remain clustered after inserts. > Clustered tables are usefull when the table is very large and there are > few different keys. > > Because the table file is already extended (2G limit) using different > files extension (.N) > how complicated (modifying the code) would it be to have the table files > split according to the cluster key? > > This would: > > Greatly improve performance when the cluster key in included in search > criteria. > Allow for a much larger table before a file has to be split (.N). > Simplify the management of symblinks (that's something else we need to > look at). > The index file for that field would no longer be required. > > Of course, there should be only one cluster key per table. > The length the "key" should be short and the number of unique key should > be low as well. > > SO... ? > > JLL > > ---------------------------(end of broadcast)--------------------------- > TIP 1: subscribe and unsubscribe commands go to majordomo@postgresql.org
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