Performance drops with Oracle 11gr2

Discussion created by JDeVos on Oct 28, 2013
Latest reply on Nov 13, 2013 by JDeVos

We have an ArcGIS Server 10.1 on which we mounted several mapservices that only uses query layers to Oracle databases (so no SDE involved and all geometries are SDO). A client application was developed with ArcGIS WPF api 2.4 that consumes these services to display maps as well as running query tasks and identify tasks.

Recently, our database servers were migrated from Oracle 10g to 11gR2. Immediately after this migration we experienced a rather spectacular rise in response time from the ArcGIS Server. The identify task seems to be the most affected functionality with response time up to 10 times longer than they used to be before migration.

We strongly suspect the new Oracle version to be at the root of this issue. To try to ascertain that, we re-mounted our old database (Oracle 10g) and set up identical map services with it. With this version of Oracle (and all other things remaining unchanged), we get back the performances that we used to have while despite our best efforts we can't bring the mapservices using Oracle 11g "up to speed".

Of course, there's always the risk that the schemas, users, permissions and/or whatever were not copied correctly from the old databases to the new ones but after pestering our database administrators almost past their point of endurance with these consideration we are fairly confident the problem lies somewhere else.

So, has anyone experienced this kind of issue? Is it,as we suspect, related to the new version of Oracle? Most importantly, how can we fix this?

Thanks for your time!