Re: IDS 11.50/AIX 5.3 Slowness Issue?

Veritas Volumes are stripred at 64K and the disk is RAID10. When using "INTO TEMP" of the same process which was used to retrive data it takes minutes verse tens of minutes. It's just when data is leaving the Database engine. Eric On Thu, May 19, 2011 at 7:08 PM, Art Kagel <art.kagel@gmail.com> wrote: > Look at the stripe block size or your SAN array that houses your chunks. > Normal filesystem files and database devices or files (including filesystem > based chunks) have very different access patterns. Where filesystems do > well with large stripe block sizes on arrays (even up to 2MB) database > files > perform much better with very small block sizes. Informix runs best with > block sizes of 32K-64K. SAN engineers love large blocks, DBAs do not. > Could be one reason. Could also be RAID5, but I don't know that. > > Art > > Art S. Kagel > Advanced DataTools (www.advancedatatools.com) > Blog: http://informix-myview.blogspot.com/ > > Disclaimer: Please keep in mind that my own opinions are my own opinions > and > do not reflect on my employer, Advanced DataTools, the IIUG, nor any other > organization with which I am associated either explicitly, implicitly, or > by > inference. 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 Thu, May 19, 2011 at 4:28 PM, Eric Rowell <erowell@gmail.com> wrote: > > > Long time no reply... Well here is where I'm at... After looking at a few > > more things I was able to see that it isn't an issue with the SAN access > of > > the database. Which was the only major change of late so was the first > > thing to be reviewed. Thank you everyone for the ideas and areas to look > > at... > > > > In the simplest form there is a large spike of disk activity when the > > session starts pulling data but the user session never sees that at the > > application side returning data. When a second session is started the SAN > > activity doubles and for each session after it increase about 5-10%. The > > server and the application continue to only ever see about 2.5M/sec each > no > > matter the speed of the disk, available memory, or CPU. As for increasing > > to 16K pages the SAN returned data to the Database engine faster but the > > user didn't see any gain at the application. > > > > So now off to start looking at communications, but I feel like I'm > missing > > something important and simple. The query takes the same amount of time > if > > using shared memory or TCP/IP on local loopback (application is local). > > > > Eric B. Rowell > > > > --20cf300257b8eb463904a3a6d80e > > > > > > > > > > ******************************************************************************* > > Forum Note: Use "Reply" to post a response in the discussion forum. > > > > > > --0016e64690da12766a04a3a91587 > > > > ******************************************************************************* > Forum Note: Use "Reply" to post a response in the discussion forum. > > -- Eric B. Rowell --002215b03d1670ad4c04a3b5520f