Oracle 11g and Documentum (Part 3)

So how did we go further? By using Oracle Enterprise Manager Grid Control (OEMGC), the queries which cause performance penalties, could be found quickly and so some extra indexes were made. But that wasn’t the only thing we saw during test. We also saw some queries running twice instead of running once. It happens for example by changing from one tab to another. Sometimes a query from the first tab was also run, before the second tab. For this behaviour we had to get support from EMC.

For other queries we need to check further, and came to the problem what Oracle has when FORCE is used for CURSOR_SHARING. The Oracle Optimizer doesn’t always like histograms with the setting of the parameter. After looking at the queries the histograms on the table DM_GROUP_R were the problem. So the statistics on the table were collected without the histogram and then these statistics were locked.

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4 Responses to “Oracle 11g and Documentum (Part 3)”

  1. adam Says:

    Hi,

    Could you please recommend the values we need to use with documentum. for optimizer_index_cost_adj (OICA), and the optimizer_index_caching (OIC) parameters.

    Thanks

    • htendam Says:

      Hi Adam,

      EMC has the note ESG102057 on Powerlink, so you need a login (see ESG102057): Since October 2012 this note states thas as of 10.2.0.3 for Oracle the best settings are to leave them default (100/0).

      We started of course also with the 95/5 settings (see also my first post about it: Documentum settings). Later on we choose 100/0 (database 11.1.0.7) and it worked better, but not all. 2 Months ago we upgraded to Oracle 11.2.0.3 and it works as a sharm. Much better than 11.1.0.7, certainly in the are where there are a lot of bind variables. Also the Plans are more stable in this version.

      So I recommended to leave the parameters at the default.

      Herald
      PS. I edit the links, the didn’t show up.

  2. adam Says:

    Hi,

    I tried to search this document on EMC community but no success. Could you please help.

    Thanks

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