High Workload System Statistics – 11gR2

Bug 9842771 exists in relation to gathering WORKLOAD system statistics on 11gR2.

See my SREADTIM and MREADTIM below.
I sure hope they’re not accurate average times in milliseconds 🙂

SQL> select * from v$version;

Oracle Database 11g Enterprise Edition Release - 64bit Production
PL/SQL Release - Production
CORE      Production
TNS for Linux: Version - Production
NLSRTL Version - Production

SQL> select * from sys.aux_stats$;

SNAME           PNAME                PVAL1 PVAL2
--------------- --------------- ---------- ------------------------------
SYSSTATS_INFO   DSTART                     03-22-2011 17:37
SYSSTATS_INFO   DSTOP                      03-22-2011 17:37
SYSSTATS_INFO   FLAGS                    1
SYSSTATS_MAIN   IOSEEKTIM               17
SYSSTATS_MAIN   SREADTIM          76000.74
SYSSTATS_MAIN   MREADTIM         90191.077
SYSSTATS_MAIN   CPUSPEED               745
SYSSTATS_MAIN   MBRC                    16
SYSSTATS_MAIN   MAXTHR           188917760
SYSSTATS_MAIN   SLAVETHR            509952

13 rows selected.

Bug description says and affected – no patch listed as currently addressing issue.

Unrealistic high values may be seen for SREADTIM and MREADTIM after
gathering system statistics.

Set the correct statistics manually using DBMS_STATS.SET_SYSTEM_STATS.

Listed as fixed in 12.1 – great…

On the plus side, system statistics can be a bit of a dilemma – do you use NOWORKLOAD? do you gather WORKLOAD running a “representative” workload? Do you gather some timings outside of the database and set manually? Or do you set manually according to the specifications? With this bug, one of those options is a non starter at least.


11 Responses to High Workload System Statistics – 11gR2

  1. Doug Burns says:

    Bug description says and affected

    Listed as fixed in 12.1 – great…

    Seems to be the story of our lives at the moment.

    • Dom Brooks says:

      What do we think about the level of bugs in 11.2?

      I suppose it’s only a X.X.0.2 and in my head maybe I’m unfairly comparing it to, say,

      • Doug Burns says:

        Our thoughts on are best left unprinted. seems better but we appear to be good at flushing out bugs in that one too.

        I’m not sure if it’s just a perception thing or whether there have been a lot of recent changes in key areas and lots of (cough) innovation where maybe more care would have been taken in the past?

        Probably just my perception.

      • Dom Brooks says:

        Was it an agile implementation do you think? 😉

  2. I thought this was on AIX only – but it looks like you’re having this on linux too ?

  3. Dom Brooks says:

    Kurt – yes, bang on, Linux.

    Metalink lists bug as generic / all platform.

  4. Centinul says:

    I’ve seen it on my Windows platforms as well.

    I e-mailed Christian Antognini back in November about this. He then promptly made a blog entry about it.

    Workload System Statistics Bug in 11.2

  5. Pingback: Fixed in 12.1 « OraStory

  6. Just thought I’d drop this in, even though its an old thread. It appears Oracle patch 9842771 addresses this issue.

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