I had opened a series of support tickets with IBM and we had been battling this issue for months. We are migrating from IDS 11.7 to 14_10 FC7 and had set identical configuration, on both. We changed a little on v14 on the following
moved to 3 temp dbspaces from 2, and from 40Gb each to 50Gb each
v11 we had all user dbspaces on 8K page size, index dbspaces (for detached indexes), temp dbspaces... System dbspaces (root, physlogs) are on 2K and blob spaces on 16K
v14 we left data on 8K pages and index dbspaces moved to 16K. Temp dbspaces on 8K (tested on 4K 8K and 16K and 8K perform better), sys dbspaces on default 2K and blobs on 16K. So the only difference from old to new is Index dbspaces on 16K,
We added a bufferpool to account for 16K pages
we have close to same bufferpool from v11 to v14 except the additional 16K pages on v14.
v11 on rhel6
v14 on rhel8
Huge pages are set the same, as well as semaphores and file descriptors for both systems.
Capacity is exactly the same 24Gb ram, 4 cores, and using raw disk for every chunk. Our data pool size is about 700Gb worth of data. Both systems are VMs
we have several data pools (3) on v11 as system had grown through time. On v14 we have only 1 huge pool where we all chunks are created for those dbspaces and tried to set 1 chunk per dbspaces to keep contiguous pages.
Migrated data over with HPLs, and done LOW stats drop dist, MED dist only and HIGH on specific indexes Dist only.
Our reports and data processing loads run almost double the time.
Some reports sorting thousands of records using temp areas for sorting run 80% slower, from 3 mins to 5.8 mins.
Processes using cursors to load data running from 20 mins to 50 mins.
Newest 4GL.ESQL installed on v14 and all 4GL code had been recompiled with no errors.
We had tried numerous variables to twitch to get to v11 performance with no luck.
I came across this post and followed it, but they are comparing apples to oranges. Here I have apples to apples (the closest I can get) and v14 performs bad compared to OLD v11
Performance of 14.10.FC5 is worse compared to 12.10 is that possible?
https://community.ibm.com/community/user/hybriddatamanagement/communities/community-home/digestviewer/viewthread?GroupId=4147&MessageKey=3a5517e6-a8c8-4d11-81b5-b098a4d0fff7&CommunityKey=cf5a1f39-c21f-4bc4-9ec2-7ca108f0a365&tab=digestviewer
I can attach any file require for analysis.
Thanks
------------------------------
Tereso Garcia
------------------------------
#Informix