Update PostgreSQL supported version in docs/database/postgres.txt

[lhc/web/wiklou.git] / docs / databases / postgres.txt

diff --git a/docs/databases/postgres.txt b/docs/databases/postgres.txt
index cec5186..c47a077 100644 (file)
--- a/docs/databases/postgres.txt
+++ b/docs/databases/postgres.txt
@@ -1,6 +1,5 @@
 This document describes the state of Postgres support in MediaWiki.
 
-
 == Overview ==
 
 Support for PostgreSQL has been available since version 1.7
@@ -10,14 +9,9 @@ Still, it is probably the most supported database after MySQL.
 Much of the work in making MediaWiki database-agnostic came
 about through the work of creating Postgres support.
 
-
 == Required versions ==
 
-The current minimum version of PostgreSQL for MediaWiki is 8.1.
-It is expected that this will be raised to 8.3 at some point,
-as 8.1 and 8.2 are nearing end of life.
-
-
+The current minimum version of PostgreSQL for MediaWiki is 9.2
 
 == Database schema ==
 
@@ -80,7 +74,6 @@ referenced directly by the code (unlike sequence names). Most of
 the indexes in the file as of this writing are there due to production
 testing of expensive queries on a busy wiki.
 
-
 == Keeping in sync with tables.sql ==
 
 The script maintenance/postgres/compare_schemas.pl should be
@@ -91,6 +84,16 @@ itself. This script has also been very useful in finding problems
 in maintenance/tables.sql itself, as it is very strict in the
 format it expects things to be in. :)
 
+== MySQL differences ==
+
+The major differences between MySQL and Postgres are represented as
+methods in the Database class. For example, implicitGroupby() is
+true for MySQL and false for Postgres. This means that in those
+places where the code does not add all the non-aggregate items
+from the SELECT clause to the GROUP BY, we can add them in, but in
+a conditional manner with the above method, as simply adding them
+all in to the main query may cause performance problems with
+MySQL.
 
 == Getting help ==