Re: explain plan parameter meanings

Cost is the optimizer cost. Card is cardinality. Byte is number of bytes processed in that particular step. Lots and lots of documentation on this.

VIVEK_SHARMA wrote:

> In the explain plan what is meant by "cost" , "card" and "byte" ?
> How may they be interpreted practically ?
> Any Docs , Links on the Same ?
>
>
> Execution Plan
> ----------------------------------------------------------
> 0 SELECT STATEMENT Optimizer=CHOOSE (Cost=6 Card=1 Bytes=76)
> 1 0 NESTED LOOPS (Cost=6 Card=1 Bytes=76)
> 2 1 NESTED LOOPS (Cost=5 Card=1 Bytes=50)
> 3 2 TABLE ACCESS (BY INDEX ROWID) OF 'GENERAL_ACCT_MAST_TA
> BLE' (Cost=3 Card=1 Bytes=17)
>
> 4 3 INDEX (UNIQUE SCAN) OF 'IDX_GAM_FORACID' (UNIQUE)
> (Cost=2 Card=1)
>
> 5 2 TABLE ACCESS (BY INDEX ROWID) OF 'ASHT_DTD' (Cost=2
> Card=5830 Bytes=192390)
>
> 6 5 INDEX (RANGE SCAN) OF 'IDX_ASHT_DTD_ACID'
> (NON-UNIQUE) (Cost=1 Card=5830)
>
> 7 1 TABLE ACCESS (BY INDEX ROWID) OF 'ASHT_TDTD' (Cost=1
> Card=2105 Bytes=54730)
>
> 8 7 INDEX (UNIQUE SCAN) OF 'IDX_ASHT_TDTD' (UNIQUE)
>
> Thanks
>

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