Re: count * performance issue
| От | sathiya psql |
|---|---|
| Тема | Re: count * performance issue |
| Дата | |
| Msg-id | f966c2ee0803052306h5e5481bdk489b2c01d0ab930b@mail.gmail.com обсуждение исходный текст |
| Ответ на | Re: count * performance issue ("A. Kretschmer" <andreas.kretschmer@schollglas.com>) |
| Ответы |
Re: count * performance issue
Re: count * performance issue |
| Список | pgsql-performance |
QUERY PLAN
------------------------------------------------------------------------------------------------------------------------------
Aggregate (cost=205756.95..205756.95 rows=1 width=0) (actual time=114675.042..114675.042 rows=1 loops=1)
-> Seq Scan on call_log (cost=0.00..193224.16 rows=5013112 width=0) (actual time=11.754..91429.594 rows=5061619 loops=1)
Filter: (call_id > 0)
Total runtime: 114699.797 ms
(4 rows)
it is now taking 114 seconds, i think because of load in my system.... any way will you explain., what is this COST, actual time and other stuffs....
On Thu, Mar 6, 2008 at 12:27 PM, A. Kretschmer <andreas.kretschmer@schollglas.com> wrote:
am Thu, dem 06.03.2008, um 12:17:55 +0530 mailte sathiya psql folgendes:> TRIGGER i can use if i want the count of the whole table, but i require forOkay, in this case a TRIGGER are a bad idea. You can use an INDEX on
> some of the rows with WHERE condition....
>
> so how to do that ???
this row. Can you show us the output for a EXPLAIN ANALYSE SELECT
count(*) from <your_table> WHERE <your_row> = ... ?
Andreas
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Andreas Kretschmer
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