Hi, the rpt_generated is a boolean value.

And you are definitely right when updating the table. The time it takes is getting longer and longer. When I do a select statement, the speed has also degraded.

Thanks.

From: Jorge Godoy <[EMAIL PROTECTED]>
To: "carter ck" <[EMAIL PROTECTED]>
CC: [EMAIL PROTECTED],  pgsql-general@postgresql.org
Subject: Re: [GENERAL] Improve Postgres Query Speed
Date: Mon, 15 Jan 2007 23:19:13 -0200

"carter ck" <[EMAIL PROTECTED]> writes:

> Hi,
>
> Thanks for reminding me. And the actual number of records is 100,000.
>
> The table is as following:

You forgot the EXPLAIN ANALYZE output...

> Table my_messages
> ---------------------------------------------------------------------------- > midx | integer | not null default
> nextval('public.my_messages_midx_seq'::text)
> msg_from           | character varying(150)       |
> msg_to               | character varying(150)       |
> msg_content       | text                                 |
> msg_status | character(1) | default 'N'::bpchar > created_dtm | timestamp without time zone | not null default now()
> processed_dtm     | timestamp without time zone |
> rpt_generated       | character(1)                | default 'N'::bpchar

Is rpt_generated a boolean column?

> Indexes:
>    "msgstat_pkey" PRIMARY KEY, btree (midx)
>    "my_messages_msgstatus_index" btree (msg_status)

If your query doesn't filter with those indices then you won't gain much with them... E.g. "UPDATE my_messages SET rpt_generated='Y' WHERE rpt_generated='N';"
won't use any of those indices and will seq scan the whole table.

--
Jorge Godoy      <[EMAIL PROTECTED]>

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