Sort

Show the query and maybe someone could help :-)

----- Original Message -----
From: "Nathan Barnett" <nbarnett@cellularphones.com>
To: <pgsql-general@postgresql.org>
Sent: Friday, July 21, 2000 2:33 PM
Subject: [GENERAL] Sort

I'm currently using v7.0.2 of PostgreSQL.

I have a query that performs a group by on three columns. The EXPLAIN of
the query is as follows:

Aggregate (cost=4116.05..4125.47 rows=94 width=24)
-> Group (cost=4116.05..4123.12 rows=942 width=24)
-> Sort (cost=4116.05..4116.05 rows=942 width=24)
-> Nested Loop (cost=0.00..4069.52 rows=942 width=24)
-> Seq Scan on click (cost=0.00..15.42 rows=942
width=8)
-> Index Scan using impression_pkey on impression
(cost=0.00..4.29 rows=1 width=16)

I need to speed up this query. I have already created an index on the

three

columns query_idx(columna, columnb,columnc). Is there some other index

that

----- Original Message -----
From: "Nathan Barnett" <nbarnett@cellularphones.com>
To: "'Mitch Vincent'" <mitch@venux.net>
Sent: Friday, July 21, 2000 3:03 PM
Subject: RE: [GENERAL] Sort

Here is the query:

SELECT Impression.AdNumber_AdNum,
Impression.Webmaster_WebmasterNum,
Impression.Banner_BannerNum, COUNT(Click.ClickNum)
AS ClickCount
FROM Impression INNER JOIN
Click ON
Impression.ImpressionNum = Click.Impression_ImpressionNum
GROUP BY Impression.AdNumber_AdNum,
Impression.Webmaster_WebmasterNum,
Impression.Banner_BannerNum

-----------------
Nathan Barnett

-----Original Message-----
From: pgsql-general-owner@hub.org [mailto:pgsql-general-owner@hub.org]On
Behalf Of Mitch Vincent
Sent: Friday, July 21, 2000 2:48 PM
To: Nathan Barnett; pgsql-general@postgresql.org
Subject: Re: [GENERAL] Sort

Show the query and maybe someone could help :-)

----- Original Message -----
From: "Nathan Barnett" <nbarnett@cellularphones.com>
To: <pgsql-general@postgresql.org>
Sent: Friday, July 21, 2000 2:33 PM
Subject: [GENERAL] Sort

I'm currently using v7.0.2 of PostgreSQL.

I have a query that performs a group by on three columns. The EXPLAIN

of

the query is as follows:

Aggregate (cost=4116.05..4125.47 rows=94 width=24)
-> Group (cost=4116.05..4123.12 rows=942 width=24)
-> Sort (cost=4116.05..4116.05 rows=942 width=24)
-> Nested Loop (cost=0.00..4069.52 rows=942 width=24)
-> Seq Scan on click (cost=0.00..15.42 rows=942
width=8)
-> Index Scan using impression_pkey on impression
(cost=0.00..4.29 rows=1 width=16)

I need to speed up this query. I have already created an index on the

three

columns query_idx(columna, columnb,columnc). Is there some other index

that

I could add which would speed up the query. There is a high frequency

in

the table of each group. Each group probably makes up 10% of the table.
Does this force a sequence scan when sorting and grouping? Basically

just

Here is the query:

SELECT Impression.AdNumber_AdNum,
Impression.Webmaster_WebmasterNum,
Impression.Banner_BannerNum, COUNT(Click.ClickNum)
AS ClickCount
FROM Impression INNER JOIN
Click ON
Impression.ImpressionNum = Click.Impression_ImpressionNum
GROUP BY Impression.AdNumber_AdNum,
Impression.Webmaster_WebmasterNum,
Impression.Banner_BannerNum

-----------------
Nathan Barnett

-----Original Message-----
From: pgsql-general-owner@hub.org [mailto:pgsql-general-owner@hub.org]On
Behalf Of Mitch Vincent
Sent: Friday, July 21, 2000 2:48 PM
To: Nathan Barnett; pgsql-general@postgresql.org
Subject: Re: [GENERAL] Sort

Show the query and maybe someone could help :-)

----- Original Message -----
From: "Nathan Barnett" <nbarnett@cellularphones.com>
To: <pgsql-general@postgresql.org>
Sent: Friday, July 21, 2000 2:33 PM
Subject: [GENERAL] Sort

I'm currently using v7.0.2 of PostgreSQL.

I have a query that performs a group by on three columns. The EXPLAIN of
the query is as follows:

Aggregate (cost=4116.05..4125.47 rows=94 width=24)
-> Group (cost=4116.05..4123.12 rows=942 width=24)
-> Sort (cost=4116.05..4116.05 rows=942 width=24)
-> Nested Loop (cost=0.00..4069.52 rows=942 width=24)
-> Seq Scan on click (cost=0.00..15.42 rows=942
width=8)
-> Index Scan using impression_pkey on impression
(cost=0.00..4.29 rows=1 width=16)

I need to speed up this query. I have already created an index on the

three

columns query_idx(columna, columnb,columnc). Is there some other index

that