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Port Bug Report: Strange choice of index, or no choice of index, for numeric keys

From: Unprivileged user <nobody>
To: pgsql-ports(at)postgresql(dot)org
Subject: Port Bug Report: Strange choice of index, or no choice of index, for numeric keys
Date: 1999-03-31 08:28:40
Message-ID: 199903310828.DAA64740@hub.org (view raw or flat)
Thread:
Lists: pgsql-ports
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                        POSTGRESQL BUG REPORT TEMPLATE
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Your name		: Philip Warner
Your email address	: pjw(at)rhyme(dot)com(dot)au

Category		: runtime: back-end: SQL
Severity		: non-critical

Summary: Strange choice of index, or no choice of index, for numeric keys

System Configuration
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  Operating System   : Linux 2.0.35

  PostgreSQL version : 6.4

  Compiler used      : gcc 2.7.2.1

Hardware:
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Pentium, 80MB
Linux Acheron 2.0.35 #8 Wed Aug 19 11:54:15 MEST 1998 i586 unknown


Versions of other tools:
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Problem Description:
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The query optimizer seems to not use indexes for indexes based on float data types, or for range queries based on integers. This seems stramge.


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Test Case:
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Create Table test(f1 float4, f2 int4);
Create Unique Index test_ix1 on test(f1);
Create Unique Index test_ix2 on test(f2);

explain select * from test where f1 = 1.0;
# This does not use an index, this may be OK since it's a float.

explain select * from test where f2 = 1;
#This uses an index, which is good.

explain select * from test where f2 > 1 and f2 < 3;
#This does not use an index, which is strange.



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Solution:
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Next:From: Gyurcsan Ferenc TamasDate: 1999-04-09 17:31:31
Subject: 6.5beta, and problems with pgaccess
Previous:From: Billy G. AllieDate: 1999-03-31 08:06:41
Subject: Bug Report - Compile errors in vacuum.c and shmem.c

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