Re: Lot of Latch Free and Enqueue Hash Chain Wait Events

  • From: Mladen Gogala <gogala.mladen@xxxxxxxxx>
  • To: Stefan Knecht <knecht.stefan@xxxxxxxxx>, Niall Litchfield <niall.litchfield@xxxxxxxxx>
  • Date: Tue, 3 Oct 2017 14:48:43 -0400

Wow! I didn't know that, because I have no experience with SE2. I don't like the ethics of such behaviour.  That looks to me like a sales pitch taken too far.

Regards


On 10/03/2017 02:13 PM, Stefan Knecht wrote:

Yes, exactly as Niall said.

The CPU limit is hard-coded into the software and they implemented it through the resource manager. Whenever you're actively using more than 16 threads, resource manager will prevent your from getting any more CPU until a thread has been freed.

I was bitten by this too when testing (deliberately producing) latch contention behavior. You can't really put too much concurrent stress on an SE2 instance, you'll simply be throttled.

Stefan





On Wed, Oct 4, 2017 at 12:07 AM, Niall Litchfield <niall.litchfield@xxxxxxxxx <mailto:niall.litchfield@xxxxxxxxx>> wrote:

    SE2 is core limited by if memory serves CPU_COUNT.

    On 3 Oct 2017 17:09, "Mladen Gogala" <gogala.mladen@xxxxxxxxx
    <mailto:gogala.mladen@xxxxxxxxx>> wrote:

        Hi Stefan, can you expand a bit on this?

        Regards


        On 10/03/2017 11:44 AM, Stefan Knecht wrote:

            Is this Standard Edition 2 ? You may be throttled by the
            database on purpose.


-- Mladen Gogala
        Oracle DBA
        Tel: (347) 321-1217 <tel:%28347%29%20321-1217>

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