We are currently running V2R12.0.3 and plan to upgrade to V2R13.10 in the near future. We are concerned to know if anyone has made this upgrade and seen any kind of spike in CPU consumption by queries on their system. We understand there are some major optimizer improvements and we should see performance improve but since we are running a pretty hot box already, we wanted to determine if those improvements may come at a CPU cost. Has anyone see this symtom or have any good / bad stories to share about their move to 13.10?
Thanks so much for your incite.
one thing do need to pay attention is the Stats version. You may need to refresh all stats on the table so that the optimizer will be able use the stats info.
We encountered this when we went from 12.0.2 to 12.0.3. The stats version changed from v3 to v4 and we did have to recollect all of our stats, which was time consuming. I'm assuming that we would need to do it again when we go to 13.10, just as a good practice but I'm not sure if the stats version is changed between 12.0.3 and 13.10.
the stats version (V4) didn't change in TD13.10, it still the same as 12.0.3.
There's no need to recollect all stats immediately, just check if there are still any outdated V3 stats left.