Fragmentation on SAN Environment (cooked file syst

All, (Sorry about the previous mime format email - I will try it once again.) I did a load of table that use to take 4 hours (20 m rows - with 2 text fields). After fragmentation with no change in anything else (divided into 20 dbspaces) the load took only 52 min. But I am not able to convince my boss that fragmentation is helping him. He wants more justification to implement fragmentation. We are using Informix 7.31 using SAN and Cooked File for the cunks (NO RAW devices - don't ask me why) Can someone guide me as to where will I find documented benefits of using Fragmentation under SAN disk environment. I am not giving too much details about the environment etc as it would be too much of unwanted information for this topic. Thanks, Sunil Thakkar. ******************************************************************************** ******************* The information in this email is confidential and may be legally privileged. Access to this email by anyone other than the intended addressee is unauthorized. If you are not the intended recipient of this message, any review, disclosure, copying, distribution, retention, or any action taken or omitted to be taken in reliance on it is prohibited and may be unlawful. If you are not the intended recipient, please reply to or forward a copy of this message to the sender and delete the message, any attachments, and any copies thereof from your system. ******************************************************************************** *******************

Thakkar, Sunil said: > > All, > > (Sorry about the previous mime format email - I will try it once again.) > > I did a load of table that use to take 4 hours (20 m rows - with 2 text > fields). After fragmentation with no change in anything else (divided into > 20 > dbspaces) the load took only 52 min. > > But I am not able to convince my boss that fragmentation is helping him. > He > wants more justification to implement fragmentation. Find a new job. -- Bye now, Obnoxio "Jesus you fucking people are hopeless." -- Double Anal "C'est pas parce qu'on n'a rien à dire qu'il faut fermer sa gueule" - Coluche did i mention i like nulls? heck, i even go so far as to say that all columns in a table except the primary key could/should be nullable. this has certain advantages, for example, if you need to insert a child record and you don't have a parent row for it, just do an insert into the parent table with the primary key value (everything else null), and voila, relational integrity is preserved. but this is, admittedly, a bit controversial among modellers. --r937, dbforums.com

I think your test is perfect documentation that Fragmentation does increase preformance. At least for the load. What I would suggest is what I have had to do in the past. You need to determine common selects and other command which access or modify this data. Using the same method you did with the load you need to document what the changes in preformance are. Also Art is so right about RAW and it seems you already are aware of this with your comment. If you could I would suggest testing the same server with RAW spaces so that you can run the same tests and time them. If your Boss is not willing to understand the gains maybe there is someone else that you can go to that could present it in a different light. Ie: if you are developent staff, go to an operations person and have them ask why your team wants to do it the way they are. -- this method isn't the best sometimes for your job... Running the test only once isn't proof. I understand it is allot of time but 5-10 runs of any given statement would be suggested to provide a proof. I would also not purely look at the run time but gaither include things like CPU, Memory and Disk performance. If your Boss is still not willing to listen then either live with it and keep it in your pocket waiting for the right time, or look for a new Boss. On 2/16/06, Thakkar, Sunil <sunil.thakkar@bearingpoint.com> wrote: > > > All, > > (Sorry about the previous mime format email - I will try it once again.) > > I did a load of table that use to take 4 hours (20 m rows - with 2 text > fields). After fragmentation with no change in anything else (divided into > 20 > dbspaces) the load took only 52 min. > > But I am not able to convince my boss that fragmentation is helping him. > He > wants more justification to implement fragmentation. > > We are using Informix 7.31 using SAN and Cooked File for the cunks (NO RAW > devices - don't ask me why) Can someone guide me as to where will I find > documented benefits of using Fragmentation under SAN disk environment. > > I am not giving too much details about the environment etc as it would be > too > much of unwanted information for this topic. > > Thanks, > > Sunil Thakkar. > > > > ******************************************************************************** ******************* > The information in this email is confidential and may be legally > privileged. > Access to this email by anyone other than the intended addressee is > unauthorized. If you are not the intended recipient of this message, any > review, disclosure, copying, distribution, retention, or any action taken > or > omitted to be taken in reliance on it is prohibited and may be unlawful. > If > you are not the intended recipient, please reply to or forward a copy of > this > message to the sender and delete the message, any attachments, and any > copies > thereof from your system. > > > ******************************************************************************** ******************* > > > > ******************************************************************************* > Forum Note: Use "Reply" to post a response in the discussion forum. > >