On Monday 11 October 2010 16:50:36 you wrote: > On 10/11/2010 3:54 PM, Neil Whelchel wrote: > > 1. A faster count(*), or something like my proposed estimate(*). > > 2. A way to get the total rows matched when using LIMIT and OFFSET before > > LIMIT and OFFSET are applied. > > The biggest single problem with "select count(*)" is that it is > seriously overused. People use that idiom to establish existence, which > usually leads to a performance disaster in the application using it, > unless the table has no more than few hundred records. SQL language, of > which PostgreSQL offers an excellent implementation, offers [NOT] > EXISTS clause since its inception in the Jurassic era. The problem is > with the sequential scan, not with counting. I'd even go as far as to > suggest that 99% instances of the "select count(*)" idiom are probably > bad use of the SQL language. I agree, I have seen many very bad examples of using count(*). I will go so far as to question the use of count(*) in my examples here. It there a better way to come up with a page list than using count(*)? What is the best method to make a page of results and a list of links to other pages of results? Am I barking up the wrong tree here? -Neil- -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
