Re: Order By Clause, Slows Query Performance?

monalee_dba wrote:
> Eg. SELECT col1, col2, col3,....col10 FROM table1;
>
> For above query If I didn't mention ORDER BY clause, then I want to know
> selected data will appear in which order by a query planner?
>
> Because I have huge size table, and when I applied ORDER BY col1, col2..in
> query the
> performance is soo bad that I can't offred.
> What should I do ? Because my requirement is data with ordered column.

A B-Tree index may help with that:
http://www.postgresql.org/docs/current/static/indexes-ordering.html
Consider a multicolumn index.

Yours,
Laurenz Albe