difference between access times of SELECT and UPDATE

From: Andrei Romazanov <romazanov.andrei_at_gfos.de>
Date: Wed, 17 Apr 2002 10:53:11 +0200
Message-ID: <a9jd07$3mno3$1@ID-70985.news.dfncis.de>

Hallo all!

can somebody explain me the difference between access times of SELECT and UPDATE,
which use the same index? I get:

by SELECT:

Execution Plan

0 SELECT STATEMENT Optimizer=CHOOSE 1 0 INDEX (RANGE SCAN) OF 'I11_BBEWV2' (NON-UNIQUE) Statistics

          0  recursive calls
          0  db block gets
          3  consistent gets
          2  physical reads
          0  redo size

by UPDATE

Execution Plan

0 UPDATE STATEMENT Optimizer=CHOOSE 1 0 UPDATE OF 'BBEWV2'
2 1 INDEX (RANGE SCAN) OF 'I11_BBEWV2' (NON-UNIQUE) Statistics

          2  recursive calls
        394  db block gets
      11203  consistent gets
      11203  physical reads
     113672  redo size

Thanks
Andrei Received on Wed Apr 17 2002 - 03:53:11 CDT