On Wed, May 21, 2008 at 10:10 AM, H. Hall <[EMAIL PROTECTED]> wrote: > Does anyone know if there is a source that provides "Big O" notation for > postgres's aggregate functions and operations? For example is count(*) = > O(1) or O(n)?
I don't know of any document containing the complexity of each aggregate, but it's sometimes left as a comment in the souce code. IIRC, COUNT (non-distinct) is currently O(n), where n also includes evaluation of tuples not represented in the final count (due to Postgres' MVCC design). -- Jonah H. Harris, Sr. Software Architect | phone: 732.331.1324 EnterpriseDB Corporation | fax: 732.331.1301 499 Thornall Street, 2nd Floor | [EMAIL PROTECTED] Edison, NJ 08837 | http://www.enterprisedb.com/ -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
