Re: explain plan parameter meanings

[Mogens N�rgaard]

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