Re: Do you use ASSM (Automatic Segment Space Management)?

From: Noons <>
Date: Mon, 3 Aug 2009 21:54:28 -0700 (PDT)
Message-ID: <>

On Aug 4, 10:07 am, ca111026 <> wrote:
> Do you use ASSM (Automatic Segment Space Management)?
> This feature was introduced in 9.2. The benefits are unclear - have
> anyone seen test results proving that in real-life situation ASSM
> produces improvements?
> At the same time ASSM has so many bugs: slow performance, spin/hang,
> excessive space usage, space leaks, etc. Just search Metalink for
> ASSM. Almost all ASSM-related bugs are "private", i.e. no additional
> information is available.
> For example:
> Bug 7575925 – ASSM blocks may be marked with wrong “freeness” (private
> bug)
> Affected version:
> Fixed in:, 11.2 (Future Release)
> Bug 5728380 – DML may spin searching for space in ASSM (private bug)
> Affected versions:,
> We had several instances where Apps Support would run large uncomitted
> DELETE (in different apps) and performance of single-row INSERT would
> deteriorate dramatically: from 10 buffer gets per INSERT  to 100,000.

We use ASSM extensively.
And most of the bugs in have patches and fixes. Which we have installed: I reckon it's a better use of our time than the silly CPUs. Received on Mon Aug 03 2009 - 23:54:28 CDT

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