Too many rows reported for index in tkprof

Hi all.

        I'm fazed by a query I've been asked to optimize.

        By creating an index, I've been able to lower EXPLAIN's cost estimate from nearly 5k to 36. Problem is, this translated in an answer time reduced from 2min 30s to 2min 20s -- too small a reduction.

        So i did autotrace:

    1271 recursive calls
   29005 db block gets
37156454 consistent gets
 1371862 physical reads

        Looking for a why, I did a tkprof:

Rows Execution Plan
------- ---------------------------------------------------

      0  SELECT STATEMENT   GOAL: CHOOSE
      0   NESTED LOOPS
   7249    NESTED LOOPS
   7249     NESTED LOOPS
   7342      TABLE ACCESS   GOAL: ANALYZED (BY INDEX ROWID) OF
                 'PS_PYMNT_VCHR_XREF'
   7342       INDEX (RANGE SCAN) OF 'PSXPYMNT_VCHR_XREF' (NON-UNIQUE)
  14589      TABLE ACCESS   GOAL: ANALYZED (BY INDEX ROWID) OF
                 'PS_VOUCHER'
  14682       INDEX   GOAL: ANALYZED (UNIQUE SCAN) OF 'PS_VOUCHER'
                  (UNIQUE)
  14496     TABLE ACCESS   GOAL: ANALYZED (FULL) OF 'PS_VENDOR'
      0    TABLE ACCESS   GOAL: ANALYZED (BY INDEX ROWID) OF
               'PS_BOLETO_BRL'
17845208     INDEX   GOAL: ANALYZED (RANGE SCAN) OF 'PS0BOLETO_BRL'
                (NON-UNIQUE)


        Oops!  Problem is, ps0boleto_brl is an index with less than 100k

        So what's wrong here? How can such a small index give such a high row number in tkprof?

        Ah, this is PeopleSoft 10 on Oracle 8.1.7.

        Thanks in advance!

--

Leandro Guimarães Faria Corcete DUTRA

Administrador de Bases de Dados      +55 (11) 4390 5383
Toyota do Brasil Ltda              ldutra_at_toyota.com.br
São Bernardo do Campo, SP                        BRASIL

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http://www.freelists.org/webpage/oracle-l Received on Tue Aug 09 2005 - 15:21:41 CDT