Re: Parameter resumable_timeout

From: Yong Huang <"Yong>
Date: Fri, 21 Oct 2016 16:30:30 +0000 (UTC)
Message-ID: <270044271.449290.1477067430749_at_mail.yahoo.com>

Luis,

The 11gR2 documentation is a little inconsistent, because the Reference manual says differently:

http://docs.oracle.com/cd/E11882_01/server.112/e40402/initparams223.htm#REFRN10239 "RESUMABLE_TIMEOUT enables or disables resumable statements and specifies resumable timeout at the system level."

Since both our tests show that simply setting the parameter alone will enable resumable sessions (even though they suddenly become enabled only when the session is suspended), I would say the Admin Guide is incorrect and the Reference is correct.

My test shows that a session that explicitly enables resumable with "alter session" command will get the "resumable state object" latch 3 times for each SQL execution, while a session that is "silently" watched by the system (i.e. you only set resumable_timeout with "alter system") will not except once at logon or until it actually runs out of space. If we only judge by this latch get, from the performance point of view, it may be slightly better to set the parameter alone. (I didn't check any other possible overhead.)

Yong Huang

---

On Fri, 10/21/16, Luis Santos <lsantos_at_pobox.com> wrote:

...

And we did several tests here (in both 11.2.0.2 and 11.2.0.4) and we conclude exactly as you: setting resumable_timeout instance wide is enough!

But the Oracle analyst said that the documentation says this.

I checked 10g, 11gR1 and 11gR2 docs. And, surprising, 10g and 11gR1 docs says, OK, that setting resumable_timeout instance wide is enough... but 11gR2 docs don't!!!
...

--
http://www.freelists.org/webpage/oracle-l

Received on Fri Oct 21 2016 - 18:30:30 CEST