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List:       solid
Subject:    Re: Multithreaded server and Linux
From:       laird () pacificrim ! net (Scott Laird)
Date:       1998-01-20 23:21:37
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In message <Pine.BSF.3.96.980120131255.26394F-100000@shell7.ba.best.com>, Brian
 Slesinsky writes:
>
>You might try doing an EXPLAIN PLAN on the delete statement.  

explain plan for delete from accesslog where accessdate < '1997-12-1';
       ID   UNIT_ID    PAR_ID JOIN_PATH UNIT_TYPE          INFO               
       --   -------    ------ --------- ---------          ----               
        1         1         0         2 JOIN UNIT                             
        2         2         1         0 TABLE UNIT         ACCESSLOG          
        3         2         1         0                    SCAN TABLE         
        4         2         1         0                    ACCESSDATE < 1997-12-1 00:00:00

>I don't think dropping _idx1 would help since the delete needs an
>index to find which rows to delete.

Well, I'm planning on deleting >50% of the rows, so I'm not all that
concerned with hitting the index.  Index hits or misses shouldn't make
a difference when you hit over half of the data, right?  Someone
speculated a month or two back that the delete would go faster without
the index (no index updates).  Of course, if I can't get rid of the
index...


Scott

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