Re: streams capture performance

From: Bradd Piontek <>
Date: Wed, 15 Oct 2008 20:50:38 -0500
Message-ID: <>

Can you post what the settings are in dba_capture_parameters? As for init.ora:
(i would increase the streams_pool_size)

How big are your redo logs and how often, on average, to do switches occur?

Bradd Piontek
  "Next to doing a good job yourself,

        the greatest joy is in having someone
        else do a first-class job under your
  • William Feather

On Wed, Oct 15, 2008 at 5:38 PM, Madhu Sreeram <>wrote:

> Hi all,
> I have a question about the performance expectation of streams capture
> process. I just implemented streams to capture DML changes in certain tables
> in our production and am not happy with the performance. If it doesn't
> improve we will be falling back to triggers. The capture latency is about
> 12hrs (capture process is reading 12hrs back archive file). Ours is a very
> high rate transaction database ( ~ 400gb/day archives). Based on the strmmon
> output during day (night time is more busy):
> Streams Pool Size = 256M
> LOG 169K (redo/sec)
> Capture rate: about 2400 lcrs captured per sec, about 4 lcrs enqueued/sec
> <idle wait events percentage> <flow control wait events percentage>: <90%I
> 0%F
> Env: on Redhat linux 4.1. six node RAC. Each node is two dual
> core AMD Opteron processors (64bit). Capture is local.
> I am not concerned with "APPLY" rate , yet, as changes to apply is expected
> to be low. I am only concerned with the captured rate.
> I have already looked at the best practices docs and made suitable
> changes. Oracle support analyst says that's the best I can get (he has not
> provided any reference documents yet) but I want to know from users who
> have implemented Streams. Are the numbers above fairly high? Is streams not
> designed for such a high log generation? What has been your experience?
> Thanks in advance.
> -Madhu Sreeram

Received on Wed Oct 15 2008 - 20:50:38 CDT

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