SELECT DISTINCT or GROUP BY? Which one is better?

Do you mean, is there a performance difference between:

SELECT DISTINCT a, b, c FROM mytable;

and

SELECT a, b, c FROM mytable GROUP BY a, b, c;

I think the CBO would generate the same plan for both of these. I don't know why you would use GROUP BY in this way - it is used to get aggregates.

Jeff

I think GROUP BY is preferable operator than the modifier DISTINCT and in many cases works faster, of course all depends on the query you have ...
I couldn't answer better to your question than this article:
http://technet.oracle.com/products/rdb/pdf/distinct_derivedtables_groupby_sort_tech_article.pdf

Venko

Thank you all for your answers and opinions.