Re: Slow UPADTE, compared to INSERT

On Thu, Dec 04, 2003 at 08:23:36PM +0000, Richard Huxton wrote:

> Ah - it's probably not the update but the IN. You can rewrite it using PG's 
> non-standard FROM:
> 
> UPDATE t1 SET status='done' FROM t_tmp WHERE t1.rec_id = t_tmp.rec_id;

Thanks for the hint. I'll try this.

> Now that doesn't explain why the update is taking so long. One fifth of a 
> second is extremely slow. Are you certain that the index is being used?

Explain shows following output:

explain update table1 set status = 'PROC' where recid = '199901';

Index Scan using table1_pkey on table1  (cost=0.00..6.01 rows=1 width=198)
   Index Cond: (recid = 199901::bigint)
   (2 rows)



-- 
Ivar Zarans