diff options
Diffstat (limited to 'doc/FAQ')
| -rw-r--r-- | doc/FAQ | 21 |
1 files changed, 17 insertions, 4 deletions
@@ -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. |