Re: SELECT INTO large FKyed table is slow - Mailing list pgsql-performance

On 29/11/10 00:46, Mario Splivalo wrote:
>
> This is the slow part:
> INSERT INTO drones_history (sample_id, drone_id, drone_log_notice,
> drone_temperature, drone_pressure)
> SELECT * FROM tmpUpdate;
>
> For 100 rows this takes around 2 seconds. For 1000 rows this takes
> around 40 seconds. For 5000 rows this takes around 5 minutes.
> For 50k rows this takes around 30 minutes! Now this is where I start
> lag because I get new CSV every 10 minutes or so.

Have you created indexes on drones_history(sample_id) and
drones_history(drone_id)? That would probably help speed up your INSERT
quite a bit if you have not done so.

Also it would be worthwhile for you to post the output of:

EXPLAIN ANALYZE INSERT INTO drones_history (sample_id, drone_id,
drone_log_notice, drone_temperature, drone_pressure)
SELECT * FROM tmpUpdate;

to the list, so we can see what is taking the time.

Cheers

Mark