Re: Max number of tables

>From: uunet!hpsgm2.sgp.hp.com!chanm (Michael CHAN) >Subject: Max number of tables >Date: Wed, 4 Aug 1993 08:40:58 GMT >X-Informix-List-Id: <news.3999> > We currently are thinking of a design where there will be 2400 database > tables. We like to know whether Informix has any upper limit on the > number of tables, the size of each table, and whether there will be > any adverse impact on the search performance if there are so many tables. Using SE or OnLine? Actually, neither engine imposes an upper limit on the number of tables, and disk space is the most likely cause of trouble. (The fussy will point out that 2**31-101 is the theoretical maximum number of tables.) If you are using OnLine, you will want to alter the next extent size of the system catalogue tables to take into account the number of entries: use ALTER TABLE Syscolumns MODIFY NEXT SIZE 64 or whatever extent size seems appropriate to you -- I haven't worked out how big the extents should be. Obviously, there will be some slight degradation of performance, because searches on the system catalogue will have to negotiate more index information to get at the description of a table, and I have to assume that more tables will be in use at any given time, so that cache rates etc will be affected. But this should not be very noticeable, and would affect any system handling that design. Why does your design need so many tables? How is anyone going to understand it? I would not like to have to deal with a database containing 2400 tables. Yours, Jonathan Leffler (johnl@informix.com) #include <disclaimer.h>