Table_cache is a pool of file descriptors held open, so the over head of opening table is not necessary since the open is cached.
Max_connections relates to table_cache because they both use descriptors. Thus at least the sum of the 2 is used by mySQL to set the ulimit of file descriptors higher then the default if executed as a user that can change the value. DVP ---- Dathan Vance Pattishall http://www.friendster.com > -----Original Message----- > From: Mark [mailto:[EMAIL PROTECTED] > Sent: Wednesday, February 02, 2005 4:09 PM > To: mysql@lists.mysql.com > Subject: Relationship between 'table_cache' and 'max_connections' > > I hope someone can clarify the relationship between > 'table_cache' and 'max_connections' (I use MySQL 4.0.23). The > manual says: > > "table_cache is related to max_connections. For example, for > 200 concurrent running connections, you should have a table > cache size of at least 200 * N, where N is the maximum > number of tables in a join. You also need to reserve some > extra file descriptors for temporary tables and files." > > Does that mean, that when table_cache is set to, say, 256, > only 256 concurrent connections can be made? I mean, is it > restrictive for the amount of connections? It seems to say > so, but since this is also said to be a CACHE value, maybe not. > > I have set table_cache to 256, max_connections to 512, and I > have an open_files_limit of 7408. Does that suffice? > > Thanks, > > - Mark > > > -- > MySQL General Mailing List > For list archives: http://lists.mysql.com/mysql > To unsubscribe: > http://lists.mysql.com/[EMAIL PROTECTED] > > -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe: http://lists.mysql.com/[EMAIL PROTECTED]
