Re: using greater than or less than vs equals in where condition - Mailing list pgsql-admin

From Tom Lane
Subject Re: using greater than or less than vs equals in where condition
Date
Msg-id 19398.1115953945@sss.pgh.pa.us
Whole thread Raw
In response to using greater than or less than vs equals in where condition  (Prasanth <dbadmin@nqadmin.com>)
Responses Re: using greater than or less than vs equals in where condition  (Prasanth <dbadmin@nqadmin.com>)
List pgsql-admin
Prasanth <dbadmin@nqadmin.com> writes:
> PG Version: 7.4.7

> explain analyze select * from data where type_code >'2' AND type_code<'4';
> [ is slow ]
> explain analyze select * from data where type_code = '3';
> [ isn't ]

Are there a whole lot of rows with type_code = 2?  If so, this is
fixed in 8.0.

2003-12-20 20:23  tgl

    * src/: backend/access/nbtree/nbtinsert.c,
    backend/access/nbtree/nbtpage.c, backend/access/nbtree/nbtsearch.c,
    include/access/nbtree.h: Improve btree's
    initial-positioning-strategy code so that we never need to step
    more than one entry after descending the search tree to arrive at
    the correct place to start the scan.  This can improve the behavior
    substantially when there are many entries equal to the chosen
    boundary value.  Per suggestion from Dmitry Tkach, 14-Jul-03.

            regards, tom lane

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