Re: Wich hardware suits best for large full-text indexed
От | Diogo Biazus |
---|---|
Тема | Re: Wich hardware suits best for large full-text indexed |
Дата | |
Msg-id | 406B15AB.4070300@ikono.com.br обсуждение исходный текст |
Список | pgsql-general |
Dann Corbit wrote: >I see that only table documentos has a unique index. Is it really so >that none of the other tables has a key to uniquely identify a record? >Perhaps the others have a unique attribute but it was never declared >when forming the index? > > I thougth that a primary key would create a unique index implictly. >I do not remember which version of PostgreSQL you are using, but there >is now a CLUSTER command. Now, I am speaking with my experience in >other database systems, and so perhaps the PostgreSQL group may find it >necessary to correct me. I have only recently began working with >PostgreSQL versions beyond 7.1.3 which had no cluster command (or at >least I was not aware of one). In other database systems, a clustered >index is incredibly valuable. In fact, a unique, clustered index is >always a silver bullet to marvelous performance. Perhaps some of the >experts can give measurements as to the effectiveness of clustering in >PostgreSQL. Here is the link for the cluster documentation: >http://www.postgresql.org/docs/current/static/sql-cluster.html > >From the description, clustering is expensive and your tables are large. >So it should be an infrequent operation. > > Sure, my pgsql is version 7.3.4 (I was obviosly mistaken when I wrote 7.4.3 in a previous email) I used to do clustering in some tables, but is a expensive operation as said... -- Diogo Biazus diogo@ikono.com.br http://www.ikono.com.br
В списке pgsql-general по дате отправления: