Large Table - Indexed - Select Time

Say you have a table that could potentially be several thousand rows or more (lots) and you need to do a select based on an indexed field or a group of indexed fields. For example, let's say the table has the following fields: content_id pKey object_id indexed integer field this_id indexed integer field another_id indexed integer field The select might look like: SELECT * FROM theTable WHERE object_id = 1 AND this_id = 2 AND another_id = 5; Is there a size of table where the selects would become slow? Or does the indexing of each of the fields take care of the problem? I am concerned about the table becoming several hundred of thousands of rows big. I'm using mysql and/or postgresql. Matt Friedman Web Applications Developer www.SpryNewMedia.com Email: matt@SpryNewMedia.com