The join table limit in MySQL is dictated by the arch that's running on. 32 tables for 32bit and 64 tables for 64bit (Somebody correct me if I'm wrong). I believe this is due to using a bitmap inside the join optimizer to keep track of tables. 64 tables is a very hefty query it makes me think that maybe you are doing something wrong when designing your application to need a join that big. When the optimizer optimizes a query it checks every possible execution path through every table so the more joins you have the more paths the opimizer has to check to find the optimal one (This isn't entirely true but close enough for my argument here).
Needing more than 1024 columns in a table also seems like bad design. Maybe you can detail more of what you are doing and why you need so many columns -Eric On Mon, 7 Mar 2005 12:21:52 -0000, Kevin Cowley <[EMAIL PROTECTED]> wrote: > Does anyone know if there is a method of circumventing or changing the > default join limits of 64 tables or 1024 columns? We're running Mysql > 4.1.4 using MyISAM tables > > Kevin Cowley > Product Development > Alchemetrics Ltd > SMARTER DATA , FASTER > Tel: 0118 902 9000 (swithcboard) > Tel: 0118 902 9099 (direct) > Web: www.alchemetrics.co.uk <http://www.alchemetrics.co.uk> > Email: [EMAIL PROTECTED] > > ************************************************************************************** > ALCHEMETRICS LIMITED (ALCHEMETRICS) > Mulberry Park, Fishponds Road, Wokingham, Berkshire, RG41 2GX > Tel: +44 (0) 118 902 9000 Fax: +44 (0) 118 902 9001 > This e-mail is confidential and is intended for the use of the addressee only. > If you are not the intended recipient, you are hereby notified that you must > not use, copy, disclose, otherwise disseminate or take any action based on > this e-mail or any information herein. > If you receive this transmission in error, please notify the sender > immediately by reply e-mail or by using the contact details above and then > delete this e-mail. > Please note that e-mail may be susceptible to data corruption, interception > and unauthorised amendment. Alchemetrics does not accept any liability for > any such corruption, interception, amendment or the consequences thereof. > ************************************************************************************** > > -- Eric Bergen [EMAIL PROTECTED] http://www.ebergen.net -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
