Database performance tuning required

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      In general, the performance of 1.4.4 is a bit on the slow side. Things are ok when we are getting cache hits - but when we have to go to the databse, we really notice the slowness.

      Looking at the database performance in a bit more detail, we have spotted a couple of issues so far.

      Two cuprits so far are:
      ============================================================
      SELECT contentent0_.contentid AS x0_0_
      FROM content contentent0_
      WHERE (contentent0_.prevver IS NULL)
      AND (contentent0_.content_status = 'current')
      AND (contentent0_.contenttype != 'MAIL')
      AND (contentent0_.contenttype != 'SPACEDESCRIPTION')
      ORDER BY contentent0_.lastmoddate DESC
      ============================================================
      This one results in a full table scan.
      Trouble is that all of the columns here have very poor selectivity.
      We will look at trying to use a bitmapped index... let you know how we go....

      The other one we have spotted so far is a bit nasty
      ============================================================
      SELECT *
      FROM (SELECT content.contentid AS contentid0_,
      content.contenttype AS contentt2_0_,
      content.title AS title0_, content.BODY AS body0_,
      content.VERSION AS version0_, content.creator AS creator0_,
      content.creationdate AS creation7_0_,
      content.lastmodifier AS lastmodi8_0_,
      content.lastmoddate AS lastmodd9_0_,
      content.prevver AS prevver0_,
      content.content_status AS content11_0_,
      content.spaceid AS spaceid0_, content.parentid AS parentid0_,
      content.blogspaceid AS blogspa14_0_,
      content.descspaceid AS descspa15_0_,
      content.pageid AS pageid0_,
      content.parentcommentid AS parentc17_0_,
      content.username AS username0_,
      content.messageid AS messageid0_,
      content.mailspaceid AS mailspa20_0_
      FROM content content INNER JOIN content b ON ( content.pageid =
      b.contentid
      AND ( b.spaceid =
      :1
      OR b.blogspaceid =
      :2
      )
      AND ( b.contenttype =
      'PAGE'
      OR b.contenttype =
      'BLOGPOST'
      )
      AND b.content_status =
      'current'
      )
      WHERE content.contenttype = 'COMMENT'
      ORDER BY content.lastmoddate DESC)
      WHERE ROWNUM <= :3
      ============================================================

        1. no-selectivity.PNG
          no-selectivity.PNG
          8 kB
        2. nasty query.PNG
          nasty query.PNG
          11 kB

              Assignee:
              Unassigned
              Reporter:
              Nick Minutello
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                Created:
                Updated:
                Resolved: