Categories
Database Development

The difference between using parallelism “/*+parallel(4)*/” in the subquery or the outer query in terms of performance in Oracle

I have the below query : select /*+parallel(4)*/ —> First Location <Desc_1> Amount, <Desc_2> Amount, <Desc_3> Amount from (select /*+parallel(4)*/ —> Second Location <Column_1>, <Column_2> from <Example_Table> where <Conditions> ) pivot(sum(Column_1) Amount for <Column_2> in (1 as <Desc_1>, 2 as <Desc_2>, 3 as <Desc_3>) ); The point is that <Example_Table> is a very big table […]