Re: Performance suggestions?

Allan,

Postgres is probably not the ideal solution to this problem.  If you'd
like to try this though, two points:

- If the table really only has 20 rows, drop the index.  If the table
really only has 20 active rows at a
time, then the planner will never use that index.
(run EXPLAIN on your query to see if it is using your index.  If not, it
is only slowing you down.)

- As said before, VACUUM frequently, maybe even every 10 seconds
(experiment with different intervals.)

Paul Tillotson

>I have a small table about 20 rows, a constant, that is receiving
>about 160 updates per second.
>The table is used to share gathered data to other process asynchronously.
>After 5 min it is 12 updates per second.
>Performance returns after a vacuum analyse.
>
>I'm using 7.4.5.
>This is the table structure
>               Table "public.lastscan"
>  Column   |            Type             | Modifiers
>-----------+-----------------------------+-----------
> pointnum  | integer                     | not null
> parameter | character varying(8)        | not null
> value     | double precision            | not null
> dt        | timestamp without time zone | not null
>Indexes:
>    "lsindex" btree (pointnum, parameter)
>
>
>