On 8/29/06, Willo van der Merwe <willo@xxxxxxxxxxxxxxxxxxxx> wrote:
and it has 743321 rows and a explain analyze select count(*) from property_values;
you have a number of options: 1. keep a sequence on the property values and query it. if you want exact count you must do some clever locking however. this can be made to be exact and very fast. 2. analyze the table periodically and query pg_class (inexact) 3. keep a control record and update it in a transaction. this has concurrency issues vs. #1 but is a bit easier to control 4. normalize other databases for example mysql optimize the special case select count(*). because of mvcc, postgresql cannot do this easily. you will find that applying any where condition to the count will slow those servers down substantially becuase the special case optimization does not apply. I am curious why you need to query the count of records in the log table to six digits of precision. merlin
