RE: Execution time in SHARED SERVER vs. DEDICATED SERVER (RAC 10gR2)

From: <>
Date: Tue, 22 Apr 2008 10:18:05 -0600
Message-ID: <002d01c8a494$74f00060$4803a8c0@BHAIRAVIPC01>

There are differences in the path and path length to the client (shared server, dispatcher, request queue, response queue, where sort area is managed, etc).

If a query runs for that long, I don't think it is a candidate to be switched over to the shared server, to begin with; you are violating the principle of sharing by dedicating the shared server to a connection!

The queries that are candidates are the ones that are cliché - ephemeral, http, etc.

From an academic point of view, all other things being equal, I would not expect that large a difference if your result set is small, I would think that some amount of time would be devoted to managing the memory spaces in SGA vs the PGA but a 50% increase is not what I would have expected. What were the wait events during that time or rather, what were the differences?


-----Original Message-----

From: [] On Behalf Of Martin Klier
Sent: Tuesday, April 22, 2008 9:23 AM
Subject: Execution time in SHARED SERVER vs. DEDICATED SERVER (RAC 10gR2)

Dear list,

Is there a difference in executing a query in dedicated vs. shared server connection?

The query plans are the same, but in shared server the query runs 1:30 min, and in dedicated mode over an hour. This is repeatable every time, and affects many queries or inserts/merges as well.

Am I missing something, or is there any know issue with that?

Regards and thanks in advance
Martin Klier

Usn's IT Blog for Linux, Oracle, Asterisk


-- Received on Tue Apr 22 2008 - 11:18:05 CDT

Original text of this message