Hi GuangYou may have to do self join. I don't know about selectivity of 'column2> some_value' predicate and so, this rewritten version could be worse. Also, make sure that it uses index on column2 using explain plan..
create table tmp_table nologging as select distinct column1 from table1 t1 where column2 > some_value and exists (select 1 from table1 t2 where t1.column1 = t2.column1 and t2.column2> some_value
and t1.row_id != t2.row_id) ; Cheers Riyaj The Pythian Group blog: http://orainternals.wordpress.com Guang Mei wrote:
Oracle 10.2.0.1.0 I have a sql that is slow to run: create table tmp_table nologging as (select column1 from table1 where column2 > some_value having count(*) > 1 group by column1); table1 is large, column2 has index on it. The count(*) value in the above query is quite big (typically in thousands) . Since I only need to check if the count(*) is large than 1, is there a way (say to use rownum somehow ) so that when count(*) gets up to 2, it stop counting (using stopkey), therefore I can have the above query run faster? Thanks.Guang--