> --- In firebird-support@yahoogroups.com, "Ivan Prenosil"
> <Ivan.Prenosil@...> wrote:
>
> > It is not question whether it helps much or not. Without ORDER BY
> > the query does not make sense at all.
>
> I've added the order by clause and retried it with IBOConsole to check
> the statistics.
>
> The query is SELECT FIRST 10 * FROM MY_TABLE WHERE COLUMN1 > 100 ORDER
> BY COLUMN1, COLUMN2
>
> The table has the index MY_INDEX on (COLUMN1, COLUMN2).
> Total number of records in the table = 100,000.
> Size of one record is approx. 3000 bytes.
> Number of rows with (Column1 > 100) is 89901.
>
> The statistics returned is as follows:
> Execution Time: 28.0766

> Prepare Time: 0.0094
> Reads: 90420
> Write: 5
> Plan: PLAN (MY_TABLE ORDER MY_INDEX INDEX (MY_INDEX))
> Rows affected: 89901
>
> PK