On 2013-01-16, Robert James <srobertjames@xxxxxxxxx> wrote: > Is there a recommended, high performance method to check for subdomains? > > Something like: > - www.google.com is subdomain of google.com > - ilikegoogle.com is not subdomain of google.com > > There are many ways to do this (lowercase and reverse the string, > append a '.' if not there, append a '%', and do a LIKE). But I'm > looking for one that will perform well when the master domain list is > an indexed field in a table, and when the possible subdomain is either > an individual value, or a field in a table for a join (potentially > indexed). write a function that does the string mangling you describe above and then index on the result. then you can use like and the index will help. -- ⚂⚃ 100% natural -- Sent via pgsql-general mailing list (pgsql-general@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-general
