Re: automated row deletion

Dave Huber wrote:
>
> I am inserting 250 rows of data (~2kbytes/row) every 5 seconds into a
> table (the primary key is a big serial). I need to be able to limit
> the size of the table to prevent filling up the disk. Is there a way
> to setup the table to do this automatically or do I have to
> periodically figure out how many rows are in the table and delete the
> oldest rows manually?
>
>
>

I think you'll find row deletes would kill your performance. For time
aged data like that, we use partitioned tables, we typically do it by
the week (keeping 6 months of history), but you might end up doing it by
N*1000 PK values or some such, so you can use your PK to determine the
partition. With a partitioning scheme, its much faster to add a new
one and drop the oldest at whatever interval you need. See
http://www.postgresql.org/docs/current/static/ddl-partitioning.html