Re: Extremely Slow Cascade Delete Operation

SemiconductorInspection=# \dt+
                            List of relations
 Schema |       Name       | Type  |  Owner   |    Size    | Description
--------+------------------+-------+----------+------------+-------------
 public | lot              | table | postgres | 8192 bytes |
 public | measurement      | table | postgres | 529 MB     |
 public | measurement_type | table | postgres | 8192 bytes |
 public | measurement_unit | table | postgres | 8192 bytes |
 public | unit             | table | postgres | 57 MB      |
(5 rows)

I can see the PostgreSQL process is occupy CPU. But how come it takes so long? There are only 1000++ row of unit, where
theirlot_id is 2. 

Seems not reasonable to me. :(

Thanks and Regards
Yan Cheng CHEOK


--- On Wed, 1/13/10, Grzegorz Jaśkiewicz <gryzman@gmail.com> wrote:

> From: Grzegorz Jaśkiewicz <gryzman@gmail.com>
> Subject: Re: [GENERAL] Extremely Slow Cascade Delete Operation
> To: "Yan Cheng Cheok" <yccheok@yahoo.com>
> Cc: pgsql-general@postgresql.org
> Date: Wednesday, January 13, 2010, 4:35 PM
> It doesn't look like it is locked, so
> it is carrying the delete out.
> However that doesn't mean, that there isn't any other
> locking
> occurring, or simply your disks are rather busy.
>
> Also, maybe the DB is rather big, what are the table sizes
> ?
> If you are using 8.4+, than do \dt+ to get an idea,
> otherwise SELECT
> pg_size_pretty(pg_total_relation_size('table_name')); for
> each table.
>
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