Generating significant "SQL*Net more data from client"

[Pankaj]

Hi Sergei

Do you have more insight about the parameter. I'm getting in ADDM
report and also I can see on Lab128. I dont' see at Statspack, AWR
report. Oracle claims it's a idle event and any higher value can be
ignored. No impact on performance. I'm seeing this on production env
while it's not seen on development env.

Any insight will be very much appreciated.


Thanks

Pankaj

[Sergei - Lab128 team]

Pankaj,

The Oracle server waits on "SQL*Net more data from client" event when
sending back data to the client. If you see these waits the network can be a
bottleneck. If your application is receiving a lot of data, then these waits
are expected because network typically is a bottleneck in bulk data move.
From Oracle server perspective, this is an idle event because it just waits
and don't spend CPU or I/O resources. From the perspective of your
application, it can indicate a problem. So my question will be: is your
application performing well or not? If not, you should investigate if the
network is at optimal performance. If network is OK, and the application is
developed in-house, then developers can analyze if the amount of data moved
is redundant and can be reduced.

You can find which SQL statement are causing "SQL*Net more data from client"
waits: in Lab128 in SQL Explorer select time interval, then in the bottom
ASH section use Tree tab. In the tree view, select "Event" as first
dimension, "SQL" as second one. Then find "SQL*Net more data from client"
event and expand this node, to show SQL statements. Select top SQL
statement, you will see full SQL text on the right. If you click on SQL ID
link, you can examine SQL statistics for this statement in the SQL Statement
window. There you can find how many rows per execution are returned and much
more.

I hope that can help,
Sergei.

Do you see