Re: primary/secondary index, difference - Mailing list pgsql-general

From Peter Eisentraut
Subject Re: primary/secondary index, difference
Date
Msg-id Pine.LNX.4.30.0106181749440.898-100000@peter.localdomain
Whole thread Raw
In response to Re: primary/secondary index, difference  ("Thalis A. Kalfigopoulos" <thalis@cs.pitt.edu>)
List pgsql-general
Thalis A. Kalfigopoulos writes:

> I was under the impression that primary index is the same as clustered index i.e. the order in the index matches the
physicalorder the records are stored on disk thus making it better when doing sequential accesses. 
> I assume that this is exactly the use of the CLUSTER command, to actually make a primary index. T/F?

No, cluster just orders the table after the index at the time it's called.
Subsequent writes will not obey that order (new rows generally go at the
end).

--
Peter Eisentraut   peter_e@gmx.net   http://funkturm.homeip.net/~peter


pgsql-general by date:

Previous
From: "Thalis A. Kalfigopoulos"
Date:
Subject: CREATE AGGREGATE state function with one argument
Next
From: will trillich
Date:
Subject: Re: OT: Apache::Session::DBI vs postgresql? --help