From: Achilleus Mantzios <achill@matrix.gatewaynet.com>
To: Tom Lane <tgl@sss.pgh.pa.us>
Cc: Stephan Szabo <sszabo@megazone23.bigpanda.com>
Cc: pgsql-performance@postgresql.org
Cc: pgsql-general@postgresql.org
Cc: pgsql-sql@postgresql.org
Subject: Re: [SQL] [PERFORM] 7.3.1 index use / performance
Date: Tue, 7 Jan 2003 20:38:17 -0200 (GMT+2)
Message-ID: <Pine.LNX.4.44.0301072034050.9687-100000@matrix.gatewaynet.com> (raw)
In-Reply-To: <14598.1041961456@sss.pgh.pa.us>
On Tue, 7 Jan 2003, Tom Lane wrote:
> There is no way that adding the filter condition should have reduced the
> estimated runtime for this plan --- reducing the estimated number of
> output rows, yes, but not the runtime. And in fact I can't duplicate
My case persists:
After clean install of the database, and after vacuum analyze,
i get
dynacom=# EXPLAIN ANALYZE select
FUELCONSUMPTION,rpm,Steam_Hours,voyage_activity,ldin from noon where
report_date between '2002-01-07' and '2003-01-07';
QUERY PLAN
-----------------------------------------------------------------------------------------------------------------------------
Index Scan using noonf_date on noon (cost=0.00..16458.54 rows=10774
width=39) (actual time=0.13..205.86 rows=7690 loops=1)
Index Cond: ((report_date >= '2002-01-07'::date) AND (report_date <=
'2003-01-07'::date))
Total runtime: 233.22 msec
dynacom=# EXPLAIN ANALYZE select
FUELCONSUMPTION,rpm,Steam_Hours,voyage_activity,ldin from noon where
report_date between '2002-01-07' and '2003-01-07' and v_code='4500';
QUERY PLAN
------------------------------------------------------------------------------------------------------------------------
Index Scan using noonf_vcode on noon (cost=0.00..3092.52 rows=83
width=39) (actual time=0.15..15.08 rows=373 loops=1)
Index Cond: (v_code = '4500'::character varying)
Filter: ((report_date >= '2002-01-07'::date) AND (report_date <=
'2003-01-07'::date))
Total runtime: 16.56 msec
(4 rows)
I thought PostgreSQL in some sense (hub.org) used FreeBSD,
is there any 4.7 FreeBSD server with pgsql 7.3.1 you could use?
==================================================================
Achilleus Mantzios
S/W Engineer
IT dept
Dynacom Tankers Mngmt
Nikis 4, Glyfada
Athens 16610
Greece
tel: +30-10-8981112
fax: +30-10-8981877
email: achill@matrix.gatewaynet.com
mantzios@softlab.ece.ntua.gr
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To: pgsql-sql@postgresql.org
Cc: achill@matrix.gatewaynet.com, tgl@sss.pgh.pa.us, sszabo@megazone23.bigpanda.com, pgsql-performance@postgresql.org, pgsql-general@postgresql.org
Subject: Re: [SQL] [PERFORM] 7.3.1 index use / performance
In-Reply-To: <Pine.LNX.4.44.0301072034050.9687-100000@matrix.gatewaynet.com>
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