Re: Performance comparison between Postgres and Greenplum

Hi Alex,

Yes, I have got 2 segments and a master host. So, in a way processing
should be faster in Greenplum.

Actually this is only a sort of Proof of Concept trial that I am carrying
out to notice differences between greenplum and postgres, if any.

For other queries though, results are satisfactory or at least comparable,
like-

select distinct so_no, serial_no from observation_all;
in postgres it takes - 1404.238 ms
in gp it takes - 1217.283 ms

Regards,

Suvankar Roy

Alex Goncharov <alex-goncharov(at)comcast(dot)net>
07/15/2009 06:07 PM
Please respond to
Alex Goncharov <alex-goncharov(at)comcast(dot)net>

To
Suvankar Roy <suvankar(dot)roy(at)tcs(dot)com>
cc
pgsql-performance(at)postgresql(dot)org
Subject
Re: [PERFORM] Performance comparison between Postgres and Greenplum

,--- You/Suvankar (Mon, 13 Jul 2009 16:53:41 +0530) ----*
| I have some 99,000 records in a table (OBSERVATION_ALL) in a Postgres DB

| as well as a Greenplum DB.
|
| The Primary key is a composite one comprising of 2 columns (so_no,
| serial_no).
|
| The execution of the following query takes 8214.016 ms in Greenplum but
| only 729.134 ms in Postgres.
| select * from observation_all order by so_no, serial_no;
|
| I believe that execution time in greenplum should be less compared to
| postgres. Can anybody throw some light, it would be of great help.

Why do you believe so?

Is your data distributed and served by separate segment hosts? By how
many? Is the network connectivity not a factor? What happens with
the times if you don't sort your result set?

-- Alex -- alex-goncharov(at)comcast(dot)net --

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