We had an issue a few years back when we upgraded the Oracle client for a
Federation Server from 11g to 12c relating to Doc ID 2247689.1. The SQL seemed
to perform the same in the database but the number of discreet connections
times the increased connection time led to a dramatic slowdown.
From: oracle-l-bounce@xxxxxxxxxxxxx <oracle-l-bounce@xxxxxxxxxxxxx> On Behalf
Of Laurentiu Oprea
Sent: Tuesday, February 21, 2023 3:46 AM
To: ORACLE-L (oracle-l@xxxxxxxxxxxxx) <oracle-l@xxxxxxxxxxxxx>
Subject: slower fetch speed with oracle client 19c vs 11g
Dear colleagues,
It started like a performance investigation where DB was blamed that after an
application upgrade queries started to be slower. We managed to isolate the
issue to only the oracle client.
They are using an application (qlikview) using OLEdb for oracle driver. When
they configure it with the oracle client 19c is fetching almost 50% slower
compared with the 11g client. Everything is identical in rest. I saw from the
sql monitor report that the same fetch size is used, probably this is dictated
by the driver which is the same in both cases.
Anyone have any idea what could be the issue here?
Appreciate your help,
Laurentiu.
