Re: PX Deq Credit: send blkd

From: Martin Klier <usn_at_usn-it.de>
Date: Fri, 19 Sep 2008 18:13:40 +0200
Message-ID: <48D3CFB4.7050803@usn-it.de>

Hi,

Christo Kutrovsky schrieb:
> So you have diagnosed that most of the consumers's processes are using 100% CPU?
There is only one of them, and it's using 99% CPU on a single core of eight.

> In that case it seems like you should increase your DOP.
Yes, I agree. That's why I asked
"How can I make it parallel on WRITING side of the statement?" initially. :)
How can I do that?
Except:

- with setting hints
- alter session enable parallel DML/DDL [parallel 32]
- alter session force parallel DML/DDL [parallel 32]

because this is what I tried so far to make the producers parallelize at all.

But having one process writing and four processes delivering data, makes the latter wait a lot.

My break-even is to have a parallelsm of 2 at the moment, sad on a box with 8 CPUs and the ability to write 1000MB/s on disks. PARALLEL up to 64 just generates a nicely scalable wait ebvent list, just as reminder, it was "PX Deq Credits: send blkd".

> btw, are you using hugepages?

Yes and no, I tried both setups so far.

Regards
Martin

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Received on Fri Sep 19 2008 - 11:13:40 CDT