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From:Heikki Tuuri Date:January 7 2003 8:53pm
Subject:Re: Calculating innodb_additional_mem_pool_size?
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----- Original Message -----
From: ""Matt Solnit"" <msolnit@stripped>
Newsgroups: mailing.database.mysql
Sent: Tuesday, January 07, 2003 8:45 PM
Subject: Calculating innodb_additional_mem_pool_size?

> Is there a good way of calculating the size for
> innodb_additional_mem_pool_size?  I would like to calculate based on the
> number of tables, rows, or whatever else I can use to pre-determine a
> value so that the warning message "allocating memory from the OS" does
> not appear.

the easiest fix is that I remove the message altogether :).

I have now removed it from 4.0.9 and 4.1.0.

Modern OS'es have a fast enough malloc so that it does not hit performance
if InnoDB has to allocate using the OS malloc(). Some old malloc
implementations were so slow that I wrote my own buddy algorithm -based
malloc. The InnoDB additional mem pool still has its use in debugging,
because InnoDB can trace its use thoroughly.

Most of the additional mem pool usage goes to tables in the data dictionary,
and connections. A rough estimate is that it is proportional to number of
tables + number of concurrent connections.

> -- Matt Solnit
> msolnit@stripped
> P.S.  This is just here to satisfy the spam filter:  MySQL

Best regards,

Heikki Tuuri
Innobase Oy
InnoDB - transactions, row level locking, and foreign key support for MySQL
See, download MySQL-Max from

Calculating innodb_additional_mem_pool_size?Matt Solnit7 Jan
Re: Calculating innodb_additional_mem_pool_size?Heikki Tuuri7 Jan