Update FAQ.

This commit is contained in:
Bruce Momjian 2001-05-11 01:33:01 +00:00
parent 1f7cb07905
commit f877cc3435
2 changed files with 19 additions and 6 deletions

21
doc/FAQ
View File

@ -1,7 +1,7 @@
Frequently Asked Questions (FAQ) for PostgreSQL
Last updated: Thu Apr 26 20:55:41 EDT 2001
Last updated: Thu May 10 21:32:49 EDT 2001
Current maintainer: Bruce Momjian (pgman@candle.pha.pa.us)
@ -74,7 +74,8 @@
4.11) What is an R-tree index?
4.12) What is the Genetic Query Optimizer?
4.13) How do I perform regular expression searches and
case-insensitive regular expression searches?
case-insensitive regular expression searches? How do I use an index
for case-insensitive searches?
4.14) In a query, how do I detect if a field is NULL?
4.15) What is the difference between the various character types?
4.16.1) How do I create a serial/auto-incrementing field?
@ -233,7 +234,7 @@
1.7) What is the latest release?
The latest release of PostgreSQL is version 7.1.
The latest release of PostgreSQL is version 7.1.1.
We plan to have major releases every four months.
@ -751,12 +752,24 @@ Maximum number of indexes on a table? unlimited
join queries through nonexhaustive search.
4.13) How do I perform regular expression searches and case-insensitive
regular expression searches?
regular expression searches? How do I use an index for case-insensitive
searches?
The ~ operator does regular expression matching, and ~* does
case-insensitive regular expression matching. The case-insensitive
variant of LIKE is called ILIKE in PostgreSQL 7.1 and later.
Case-insensitive equality comparisons are normally expressed as:
SELECT *
FROM tab
WHERE lower(col) = 'abc'
This will not use an standard index. However, if you create a
functional index, it will be used:
CREATE INDEX tabindex on tab (lower(col));
4.14) In a query, how do I detect if a field is NULL?
You test the column with IS NULLIS NOT NULL.

View File

@ -12,7 +12,7 @@
alink="#0000FF">
<H1>Frequently Asked Questions (FAQ) for PostgreSQL</H1>
<P>Last updated: Thu Apr 26 20:55:41 EDT 2001</P>
<P>Last updated: Thu May 10 21:32:49 EDT 2001</P>
<P>Current maintainer: Bruce Momjian (<A href=
"mailto:pgman@candle.pha.pa.us">pgman@candle.pha.pa.us</A>)<BR>
@ -312,7 +312,7 @@
<H4><A name="1.7">1.7</A>) What is the latest release?</H4>
<P>The latest release of PostgreSQL is version 7.1.</P>
<P>The latest release of PostgreSQL is version 7.1.1.</P>
<P>We plan to have major releases every four months.</P>