From 5458bd2fa55848e5fa0ce1d11b79310669f8ea20 Mon Sep 17 00:00:00 2001
From: Bruce Momjian <bruce@momjian.us>
Date: Fri, 14 Feb 2003 04:07:46 +0000
Subject: [PATCH] Update FAQ.
---
doc/FAQ | 2 +-
doc/src/FAQ/FAQ.html | 39 ++++++++++++++++++---------------------
2 files changed, 19 insertions(+), 22 deletions(-)
diff --git a/doc/FAQ b/doc/FAQ
index c75ee9d62b9..580ced306b3 100644
--- a/doc/FAQ
+++ b/doc/FAQ
@@ -1,7 +1,7 @@
Frequently Asked Questions (FAQ) for PostgreSQL
- Last updated: Mon Jan 27 01:24:42 EST 2003
+ Last updated: Thu Feb 13 23:07:35 EST 2003
Current maintainer: Bruce Momjian (pgman@candle.pha.pa.us)
diff --git a/doc/src/FAQ/FAQ.html b/doc/src/FAQ/FAQ.html
index b1ca31a3855..5a2025f88bd 100644
--- a/doc/src/FAQ/FAQ.html
+++ b/doc/src/FAQ/FAQ.html
@@ -10,7 +10,7 @@
alink="#0000ff">
<H1>Frequently Asked Questions (FAQ) for PostgreSQL</H1>
- <P>Last updated: Thu Dec 5 00:47:26 EST 2002</P>
+ <P>Last updated: Thu Feb 13 23:07:35 EST 2003</P>
<P>Current maintainer: Bruce Momjian (<A href=
"mailto:pgman@candle.pha.pa.us">pgman@candle.pha.pa.us</A>)<BR>
@@ -318,7 +318,7 @@
<H4><A name="1.7">1.7</A>) What is the latest release?</H4>
- <P>The latest release of PostgreSQL is version 7.2.3.</P>
+ <P>The latest release of PostgreSQL is version 7.3.1.</P>
<P>We plan to have major releases every four months.</P>
@@ -536,8 +536,8 @@
interface?</H4>
Yes, there are several graphical interfaces to PostgreSQL available.
- These include PgAccess <a href="http://www.pgaccess.com">
- http://www.pgaccess.com</a>), PgAdmin II (<a
+ These include PgAccess <a href="http://www.pgaccess.org">
+ http://www.pgaccess.org</a>), PgAdmin II (<a
href="http://www.pgadmin.org">http://www.pgadmin.org</a>,
Win32-only), RHDB Admin (<a
href="http://sources.redhat.com/rhdb/">http://sources.redhat.com/rhdb/
@@ -547,10 +547,6 @@
http://phppgadmin.sourceforge.net/ </a>), a web-based interface to
PostgreSQL.
- <P>We have a nice graphical user interface called PgAccess which can
- also be used as a report generator. The Web page is
- <A href="http://www.pgaccess.org/">http://www.pgaccess.org/</A>.</P>
-
<H4><A name="2.4">2.4</A>) What languages are able to communicate with
PostgreSQL?</H4>
@@ -757,11 +753,6 @@
the number of allowed backend processes is so your system won't run
out of resources.</P>
- <P>In PostgreSQL versions prior to 6.5, the maximum number of
- backends was 64, and changing it required a rebuild after altering
- the MaxBackendId constant in
- <I>include/storage/sinvaladt.h</I>.</P>
-
<H4><A name="3.9">3.9</A>) What is in the <I>pgsql_tmp</I> directory?</H4>
<P>This directory contains temporary files generated by the query
@@ -947,6 +938,10 @@
LIMIT 1;
</PRE>
+ <P>If you believe the optimizer is incorrect in choosing a
+ sequential scan, use <CODE>SET enable_seqscan TO 'off'</CODE> and
+ run tests to see if an index scan is indeed faster.</P>
+
<P>When using wild-card operators such as <SMALL>LIKE</SMALL> or
<I>~</I>, indexes can only be used in certain circumstances:</P>
<UL>
@@ -1039,10 +1034,10 @@
<PRE>
Type Internal Name Notes
--------------------------------------------------
-"char" char 1 character
-CHAR(n) bpchar blank padded to the specified fixed length
VARCHAR(n) varchar size specifies maximum length, no padding
+CHAR(n) bpchar blank padded to the specified fixed length
TEXT text no specific upper limit on length
+"char" char one character
BYTEA bytea variable-length byte array (null-byte safe)
</PRE>
@@ -1056,11 +1051,13 @@ BYTEA bytea variable-length byte array (null-byte safe)
stored out-of-line by <SMALL>TOAST</SMALL>, so the space on disk
might also be less than expected.</P>
- <P><SMALL>CHAR(n)</SMALL> is best when storing strings that are
- usually the same length. <SMALL>VARCHAR(n)</SMALL> is best when
- storing variable-length strings but it limits how long a string can
- be. <SMALL>TEXT</SMALL> is for strings of unlimited length, maximum
- 1 gigabyte. <SMALL>BYTEA</SMALL> is for storing binary data,
+ <SMALL>VARCHAR(n)</SMALL> is best when storing variable-length
+ strings and it limits how long a string can be. <SMALL>TEXT</SMALL>
+ is for strings of unlimited length, with a maximum of one gigabyte.
+ <P><SMALL>CHAR(n)</SMALL> is for storing strings that are all the
+ same length. <SMALL>CHAR(n)</SMALL> pads with blanks to the specified
+ length, while <SMALL>VARCHAR(n)</SMALL> only stores the characters
+ supplied. <SMALL>BYTEA</SMALL> is for storing binary data,
particularly values that include <SMALL>NULL</SMALL> bytes. These
types have similar performance characteristics.</P>
@@ -1286,7 +1283,7 @@ BYTEA bytea variable-length byte array (null-byte safe)
</PRE>
For this to be fast, <CODE>subcol</CODE> should be an indexed column.
- We hope to fix this limitation in a future release.
+ This preformance problem will be fixed in 7.4.
<H4><A name="4.23">4.23</A>) How do I perform an outer join?</H4>
--
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