I run autotrace on a select statement. I want to know what mean
Cost, Card, Bytes in the output of the Autotrace.


0 SELECT STATEMENT Optimizer=CHOOSE (Cost=1 Card=14 Bytes=98)
1 0 NESTED LOOPS (Cost=1 Card=14 Bytes=98)
2 1 TABLE ACCESS (FULL) OF 'EMP' (Cost=1 Card=14 Bytes=70)
3 1 INDEX (UNIQUE SCAN) OF 'PK_DEPT' (UNIQUE)


Thank's
Bensmail