On Tue, May 15, 2012 at 3:58 PM, Robert James <srobertjames@xxxxxxxxx> wrote: > I see how CLUSTER can speed up a range query (eg WHERE val < 30), > because it groups those records in contiguous pages. > > What about where I'm only pulling one record back? Eg WHERE user_id = > 100. Is there any benefit to a CLUSTER in that case? Is there > anything lost if I CLUSTER on a different index? > > If my usage is: A large number of single record SELECTs based on > user_id, and a small number of range queries, usually based on val, > would I be best off CLUSTERing on val? I mostly already answered this on your cluster thread but yeah -- in this case you'd probably want to CLUSTER on val in this case. Lack of logical tuple grouping on the primary key is one of the big reasons why *not* to use surrogate keys that everybody tends to overlook. There are many other good reasons to use surrogates though. merlin -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
