Re: Enqueue Diagnosis

From: Yong Huang <yong321_at_yahoo.com>
Date: 13 Aug 2003 18:39:28 -0700
Message-ID: <b3cb12d6.0308131739.78922cb@posting.google.com>

"Anton Buijs" <remove_aammbuijs_at_xs4all.nl> wrote in message news:<3f3a53ed$0$49100$e4fe514c_at_news.xs4all.nl>...
> Chuck <chuckh_at_softhome.net> schreef in berichtnieuws
> Xns93D65C1FEFDF6chuckhsofthomenet_at_130.133.1.4...
> | mccmx_at_hotmail.com (Matt) wrote in
> | news:cfee5bcf.0308130317.75036b6c_at_posting.google.com:
> |
> |
> | What's wrong with querying dba_waiters/dba_blockers? Run the query from a
> | shell script and email yourself the output.
>
> The problem is that these views are *so slow* when you query them.
> I don't understand why.

Hi, Anton,

In 8.1, dba_waiters is known to run slow. Look at Note:122567.1. The workaround is to set your optimizer_goal to RULE first. Or replace the view with the code in that note.

Many queries on data dictionary views need to have either a RULE hint, or an ORDERED hint (optionally with a few USE_NL hints), to speed up.

Yong Huang Received on Wed Aug 13 2003 - 20:39:28 CDT