IDS 11.5
I'm trying to run performance tests. However, I need to be able to repeatedly run a query without it being cached in the buffer. For example, I run query1 and it takes 6 seconds, I don't change anything... run query1 again and it takes sub second. I want to be able to run as though it was not cached. Besides bouncing the informix instance, is there a command I can run? Please let me know. Thank you in advance for your help! -Thinh
No. The only way to clear the caches out completely is to bounce the instance. Art Art S. Kagel Oninit (www.oninit.com) IIUG Board of Directors (art@iiug.org) See you at the 2010 IIUG Informix Conference April 25-28, 2010 Overland Park (Kansas City), KS www.iiug.org/conf Disclaimer: Please keep in mind that my own opinions are my own opinions and do not reflect on my employer, Oninit, the IIUG, nor any other organization with which I am associated either explicitly or implicitly. Neither do those opinions reflect those of other individuals affiliated with any entity with which I am affiliated nor those of the entities themselves. On Wed, Dec 16, 2009 at 2:34 PM, THINH TRAN <thinh.tran@digitalinsight.com>wrote: > I'm trying to run performance tests. However, I need to be able to > repeatedly > run a query without it being cached in the buffer. For example, I run > query1 > and it takes 6 seconds, I don't change anything... run query1 again and it > takes sub second. I want to be able to run as though it was not cached. > Besides bouncing the informix instance, is there a command I can run? > Please > let me know. Thank you in advance for your help! > > -Thinh > > > > ******************************************************************************* > Forum Note: Use "Reply" to post a response in the discussion forum. > > --00151743f8847976bd047adda6cd
Thinh, I always bonce the instance. I'm not aware of any other way, other then filling the buffers with none related data in between tests (this would push the other data out of the buffers)... We will see if anyone comes up with something else. An idea to limit the number of times I have to restart: I look for records which are on different data pages which I can use the query to select. Then I can test the query a few times before having to restart. On large tables I can have hundreds (normally only 10) of options and I keep track of the run time for each. That or I work off hours so the developers aren't in the way of my testing. 6 seconds isn't bad but I'm guessing your trying to make it much faster.... Good luck. Eric B. Rowell On Wed, Dec 16, 2009 at 2:34 PM, THINH TRAN <thinh.tran@digitalinsight.com>wrote: > I'm trying to run performance tests. However, I need to be able to > repeatedly > run a query without it being cached in the buffer. For example, I run > query1 > and it takes 6 seconds, I don't change anything... run query1 again and it > takes sub second. I want to be able to run as though it was not cached. > Besides bouncing the informix instance, is there a command I can run? > Please > let me know. Thank you in advance for your help! > > -Thinh > > > > ******************************************************************************* > Forum Note: Use "Reply" to post a response in the discussion forum. > > -- Eric B. Rowell --0016e6d9a3ac5f41b8047adddc64
And in case you have your chunks in a file system (rather than on raw devices), you may want to think about clearing out the file system buffer cache of the OS as well ... Often you can do so by "unmount" followed by "mount" of the respective file system ... Regards, Martin -- Martin Fuerderer IBM Informix Development Munich, Germany Information Management IBM Deutschland Research & Development GmbH Chairman of the Supervisory Board: Martin Jetter Board of Management: Dirk Wittkopp Corporate Seat: Boeblingen, Germany Reg.-Gericht: Amtsgericht Stuttgart, HRB 243294 ids-bounces@iiug.org wrote on 12/16/2009 08:38:31 PM: > > No. The only way to clear the caches out completely is to bounce the > instance. > > Art > > Art S. Kagel > Oninit (www.oninit.com) > IIUG Board of Directors (art@iiug.org) > > See you at the 2010 IIUG Informix Conference > April 25-28, 2010 > Overland Park (Kansas City), KS > www.iiug.org/conf > > Disclaimer: Please keep in mind that my own opinions are my own > opinions and > do not reflect on my employer, Oninit, the IIUG, nor any other organization > with which I am associated either explicitly or implicitly. Neither do > those opinions reflect those of other individuals affiliated with > any entity > with which I am affiliated nor those of the entities themselves. > > On Wed, Dec 16, 2009 at 2:34 PM, THINH TRAN > <thinh.tran@digitalinsight.com>wrote: > > > I'm trying to run performance tests. However, I need to be able to > > repeatedly > > run a query without it being cached in the buffer. For example, I run > > query1 > > and it takes 6 seconds, I don't change anything... run query1 > again and it > > takes sub second. I want to be able to run as though it was not cached. > > Besides bouncing the informix instance, is there a command I can run? > > Please > > let me know. Thank you in advance for your help! > > > > -Thinh > > > > > > > > > ******************************************************************************* > > Forum Note: Use "Reply" to post a response in the discussion forum. > > > > > > --00151743f8847976bd047adda6cd > > > ******************************************************************************* > Forum Note: Use "Reply" to post a response in the discussion forum. >
No, = From: "THINH TRAN" <thinh.tran@digitalinsight.com> = = To: ids@iiug.org = = Date: 12/16/2009 01:35 PM = = Subject: IDS 11.5 [18408] = = Sent by: ids-bounces@iiug.org = = I'm trying to run performance tests. However, I need to be able to repeatedly run a query without it being cached in the buffer. For example, I run query1 and it takes 6 seconds, I don't change anything... run query1 again and= it takes sub second. I want to be able to run as though it was not cached.= Besides bouncing the informix instance, is there a command I can run? Please let me know. Thank you in advance for your help! -Thinh ***********************************************************************= ******** Forum Note: Use "Reply" to post a response in the discussion forum. =