Re: Slow update SQL

bungsu,

That does make the query work a bit faster. Thanks!

On Mon, 2006-02-27 at 09:42 +0700, Bungsuputra Linan wrote:

> Hi Ken,
>
> I used to have the same problem. In my computer, using date_part in WHERE
> clause will always slow down the system when the table has plenty of rows.
>
> My suggestion is try to change the query to:
> ... WHERE dxdate >= '2001-01-01';
>
> I hope this helps.
>
> Regards,
> bungsu
>
> ----- Original Message -----
> From: Ken Hill
> To: Postgres Help
> Sent: Tuesday, February 14, 2006 8:48 AM
> Subject: [SQL] Slow update SQL
>
>
> I'm experiencing a very slow query. The table contains 611,564 rows of data.
> I vaccumed the table:
>
> VACUUM ANALYZE ncccr10;
>
> SELECT count(*) FROM ncccr10;
> count
> --------
> 611564
> (1 row)
>
> When I try to analyze the query plan with:
>
> EXPLAIN ANALYZE
> UPDATE ncccr10
> SET key = facilityno||'-'||
> lastname||'-'||
> sex||'-'||
> ssno||'-'||
> birthdate||'-'||
> primarysit||'-'||
> dxdate||'-'||
> morphology3
> WHERE date_part('year',dxdate) > '2000';
>
> The query just never finishes (even 1 hour later). The colum key100 is
> indexed, and I'm setting the value of this
> column from other columns. Why is this so slow?
>