Use of Swap Memroy
Hi, will it help to use swap memory on MYSQL's VM. We are in planning to use 10GB RAM and 10 GB as swap on a perticular server? thanx
Re: Use of Swap Memroy
Many thanks, I wanted to finalized on RAM requirement for one of my server so do we have any calculation method to choose intial RAM? On Fri, Dec 2, 2011 at 12:06 AM, Reindl Harald h.rei...@thelounge.netwrote: Am 01.12.2011 18:56, schrieb Stdranwl: Hi, will it help to use swap memory on MYSQL's VM. We are in planning to use 10GB RAM and 10 GB as swap on a perticular server? thanx SWAP is always bad and should only be a reserve so normally you should have as much memory as needed for the application (per-connections-buffersxmac_connetions, key_buffer_size, buffer_pool) and 20-40% reserve, additional i wuld recommend 1-2 GB SWAP to help the OS in stress-situations but never, independent for which service, you should see SWAp as additional memory because if it is heavily used/needed the performance will suck
Re: delete syntax
DROP USER command is the only command to remove any user and its association from all other tables. Cheers On Fri, Dec 2, 2011 at 8:22 AM, Reindl Harald h.rei...@thelounge.netwrote: ALWAYS start with select * from mysql.user where user='mail_admin' and host like '\%'; and look what records are affected to make sure the were-statement works as expected and then use CURSOR UP and edit the last command to delete from not only doing this while unsure with escapes protects you against logical mistakes like forget a and column=1 and get 1000 rows affected with no way back Am 02.12.2011 03:43, schrieb Shiva: delete from mysql.user where user='mail_admin' and host like '\%' ; Note: I haven't tested it and since % is a wildcard you need to escape it. On Thu, Dec 1, 2011 at 6:09 PM, Tim Dunphy bluethu...@jokefire.com wrote: Thanks but I probably should have noted that I only want to delete the wildcard user. There are other users I would prefer to not delete. mysql select user,host from mysql.user where user='mail_admin'; ++---+ | user | host | ++---+ | mail_admin | % | | mail_admin | 127.0.0.1 | | mail_admin | localhost | | mail_admin | localhost.localdomain | ++---+ 4 rows in set (0.00 sec)
Global Variables
Hi I can see different values when I run show global variables like . show variables like .? could any body please revert me on the scope and how they works?
Re: Global Variables
Ok it is fine . but I just wanted to to know on following: Let say sort_buffer_size is set 10 M and Globally it is set 3G so how it will be used? On Wed, Nov 30, 2011 at 8:47 PM, Paul DuBois paul.dub...@oracle.com wrote: On Nov 30, 2011, at 4:04 AM, Stdranwl wrote: Hi I can see different values when I run show global variables like . show variables like .? could any body please revert me on the scope and how they works? These sections of the MySQL manual may be of interest: http://dev.mysql.com/doc/refman/5.5/en/using-system-variables.html http://dev.mysql.com/doc/refman/5.5/en/show-variables.html http://dev.mysql.com/doc/refman/5.5/en/set-option.html Individual variable descriptions are here: http://dev.mysql.com/doc/refman/5.5/en/server-system-variables.html Dynamic means a variable can be set at runtime with SET. -- Paul DuBois Oracle Corporation / MySQL Documentation Team Madison, Wisconsin, USA www.mysql.com
Opentaps database
Did anybody from group get a chance to work on opentaps' DB ... It will be great help if some config changes and optimization tricks, somebody can suggest me keeping in mind 64G RAM?
Re: Global Variables
So then no use of setting 3G sort buffer in my.cnf untill system will take a rebot? I was in the impression that 10M will be used and it will be scratched to 3G whenever required as same is set globally? On Wed, Nov 30, 2011 at 10:22 PM, Paul DuBois paul.dub...@oracle.comwrote: The session value (10M in your case) will be used for queries issued in that session. On Nov 30, 2011, at 9:38 AM, Stdranwl wrote: Ok it is fine . but I just wanted to to know on following: Let say sort_buffer_size is set 10 M and Globally it is set 3G so how it will be used? On Wed, Nov 30, 2011 at 8:47 PM, Paul DuBois paul.dub...@oracle.com wrote: On Nov 30, 2011, at 4:04 AM, Stdranwl wrote: Hi I can see different values when I run show global variables like . show variables like .? could any body please revert me on the scope and how they works? These sections of the MySQL manual may be of interest: http://dev.mysql.com/doc/refman/5.5/en/using-system-variables.html http://dev.mysql.com/doc/refman/5.5/en/show-variables.html http://dev.mysql.com/doc/refman/5.5/en/set-option.html Individual variable descriptions are here: http://dev.mysql.com/doc/refman/5.5/en/server-system-variables.html Dynamic means a variable can be set at runtime with SET. -- Paul DuBois Oracle Corporation / MySQL Documentation Team Madison, Wisconsin, USA www.mysql.com -- Paul DuBois Oracle Corporation / MySQL Documentation Team Madison, Wisconsin, USA www.mysql.com
