Re: Improve Postgres Query Speed

"carter ck" <carterck32(at)hotmail(dot)com> 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 <jgodoy(at)gmail(dot)com>