Explain Plan question...

From: Sean <dolans_at_my-deja.com>
Date: Thu, 30 Mar 2000 02:18:31 GMT
Message-ID: <8budha$e1e$1_at_nnrp1.deja.com>

[Quoted] I am using the TOAD software and just found the explain plan item. Looks great, but I am having trouble understanding how to interpret the [Quoted] results. Is there any documentation or websites that can help point this out?

I am curious what I should be looking for. And is a RANGE SCAN better [Quoted] or worse than a UNIQUE SCAN?

Thanks,
Sean

PS I'll put the output below in case anyone would like to comment. Thanks again.

SELECT STATEMENT Optimizer=CHOOSE
  SORT (ORDER BY)
    NESTED LOOPS

      NESTED LOOPS
        NESTED LOOPS
          NESTED LOOPS
            NESTED LOOPS
              TABLE ACCESS (BY INDEX ROWID) OF KNOW
                INDEX (RANGE SCAN) OF XIF180KNOW (NON-UNIQUE)
              TABLE ACCESS (BY INDEX ROWID) OF STAT_KNOW_REC
                INDEX (UNIQUE SCAN) OF SYS_C006796 (UNIQUE)
            INDEX (UNIQUE SCAN) OF SYS_C006685 (UNIQUE)
          TABLE ACCESS (BY INDEX ROWID) OF SYSTEM_GRP_USER
            INDEX (RANGE SCAN) OF XIF127SYSTEM_GRP_USER (NON-UNIQUE)
        INDEX (UNIQUE SCAN) OF SYS_C006629 (UNIQUE)
      INDEX (UNIQUE SCAN) OF SYS_C006719 (UNIQUE)

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Before you buy. Received on Thu Mar 30 2000 - 04:18:31 CEST