MINUS operator - How it works.!!??

Hi,
Could someone please tell how MINUS operator works for comparing and giving non-matching records in Table1? Does MINUS operator compares all records of Table1 with all records of Table2 to give differences? Say, i've got 2 tables - no keys defined on them. No PK and UK. Now MINUS operator will pick which columns for comparison? Having a PK/UK, i see it as comparing these keys and susequently the rest of fields for matcing key records, thereby reporting non-matching records from Table1. Say, if both Table1 and Table2 have 300,00 records each. Now how many comparisons would this result in?

Someone please light a bulb on me... or direct me to some good links that would clear my doubts on this.

TIA Received on Mon Nov 17 2003 - 13:08:28 CET