Re: [GENERAL] Slow joins

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От Dustin Sallings
Тема Re: [GENERAL] Slow joins
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Msg-id Pine.SGI.3.95.990805094014.24447B-100000@bleu.west.spy.net
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Ответ на Slow joins  (Roberto Moreda <moreda@sanluis.net>)
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On Thu, 5 Aug 1999, Roberto Moreda wrote:

    Have you vacuumed?  Can you post your actual explain?

    BTW, I would strongly encourage you to use boolean for this.  I've
seen tables that used CHAR for such things and code that had to check for
one of the following values:

yYtT1 or nNfF0

    Boolean can't have this problem.

# I have a speed problem with a query that involves 3 tables.
# I focused the problem in a scan in a big table (70000 rows) using a indexed
# field. The field is a "flag" field which values only can be 'Y' or 'N'.
# In the query I look for the values 'N' (average value = 10 rows over the
# 70000). Postgres does a Seq Scan.
#
# How can I speed up that scan? How can I force the use of the index?
#
# Where can I found general recomendations to speed up queries?
#
# TIA
#
#     Roberto
#
# --
# Roberto Moreda
# Resp. Dpto. Inform�tica Handem/San Luis
# Tlf +34 981 779000
# Fax +34 981 779022
# Pol. Piadela Sur, Autov�a A6 Sal.567
# 15300 Betanzos (A Coru�a) - Espa�a
#
#

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pub  1024/3CAE01D5 1994/11/03 Dustin Sallings <dustin@spy.net>
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