Re: [ADMIN] Fast Deletion For Large Tables

On Wed, 2 Oct 2002, Raymond Chui wrote:

> I have some tables with huge data.
> The tables have column timestamp and float.
> I am try to keep up to 6 day of data values.
> What I do is execute SQL below from crontab (UNIX to
> schedule commands).
>
> BEGIN;
> DELETE FROM table_1 WHERE column_time < ('now'::timestamp - '6
> days'::interval);
> .....
> DELETE FROM table_n WHERE column_time < ('now'::timestamp - '6
> days'::interval);
> COMMIT;
>
>
> Everything is running fine, except take long time to finish.
> Because some tables stored values from 50,000 to 100,000 rows
> Some deletion need to deleted up to 45,000 rows.
>
> So I am thinking just delete the rows by their row number or row ID,
> like
>
> DELETE FROM a_table WHERE row_id < 45000;
>
> I know there is row_id in Oracle.
> Is there row_id for a table in Postgres?

Not really of that sort IIRC Oracle's row_id definition, although you
could probably fake something with a sequence.