MySQL Bugs: #44193: Since 6.0.9 default falcon_page_cache

Bug #44193	Since 6.0.9 default falcon_page_cache_size is 256MB rather than 4MB
Submitted:	9 Apr 2009 19:59	Modified:	17 Aug 2009 19:47
Reporter:	Peter Brawley (Basic Quality Contributor)	Email Updates:
Status:	Closed	Impact on me:	None
Category:	MySQL Server: Documentation	Severity:	S3 (Non-critical)
Version:	6.0.10	OS:	Any
Assigned to:	MC Brown	CPU Architecture:	Any
Tags:	qc

Description:
Since 6.0.9 default falcon_page_cache_size is 256MB rather than the currently documented 4MB. 

This adds 252MB to the server's memory footprint, a nasty surprise for many a user, and difficult to track down.

How to repeat:
As above

Suggested fix:
Correct the documentation to include a note on when to go with the default and when to override it my.cnf/ini.

What exact platfrom and binaries do you use? 

When I build from source I have by default:

openxs@suse:/home2/openxs/dbs/6.0> bin/mysql -uroot test
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 2
Server version: 6.0.11-alpha-debug Source distribution

Type 'help;' or '\h' for help. Type '\c' to clear the buffer.

mysql> show variables like 'falcon_page%';
+------------------------+---------+
| Variable_name          | Value   |
+------------------------+---------+
| falcon_page_cache_size | 4194304 |
| falcon_page_size       | 4096    |
+------------------------+---------+
2 rows in set (0.03 sec)

> What exact platfrom and binaries do you use? 

WinXP SP2, Install Binary 6.0.10 for Windows.

See final note in http://bugs.mysql.com/bug.php?id=42510:

Pushed into 6.0.10-alpha (revid:alik@sun.com-20090211182317-uagkyj01fk30p1f8) (version source revid:hky@sun.com-20090203204730-3k0pc0uoxp6wqr1i) (merge vers: 6.0.10-alpha) (pib:6)

Thank you for a reasonable documentation request.

There is already a note in the documentation about the change in size in the table associated with the config option (http://dev.mysql.com/doc/refman/6.0/en/se-falcon-configuration.html#sysvar_falcon_page_cac...), but it is currently docced against 6.0.10. This is per the push attached to Bug #42510 and Bug #36442. 

There is also a changelog entry for this item against 6.0.10. 

Checking the 6.0.9 code, the default is still 4MB, the change to 250MB is in 6.0.10.