Contribution: Drupal 6.11 with postgreSQL and usage of postgres schema

Contribution: Drupal 6.11 with postgreSQL and usage of postgres schema

(http://www.postgresql.org/docs/8.3/interactive/sql-createschema.html)
Allows grouping of all tables (indices etc.) belonging to one (virtual) drupal Site.

Benefits:
- not getting hundrets of drupal database tables with prefixed names in your database instance.
- Database dump can be made on specific drupal sites (for example to handout
your customer his table data)
- database tables belonging to a drupal site can easily removed (drop schema ... cascade ...)
instead of manually entering all the table names with prefixes.

I suggest changes to drupal core for this.
Attached is a contribution of 2 changed drupal code (diff's) files:
includes/database.inc
includes/database.pgsql.inc

Platform:
System : FreeBSD 7.2-STABLE
Database: postgreSQL 8.2.3
PHP : Version => 5.2.9
Drupal : 6.11

USAGE - How to add a virtual drupal site:

1. Do as like normal (prepare sites/www.mydomain.com/...)

2. in postgres create a schema:
CREATE SCHEMA schemaname AUTHORIZATION username;

You can list all schema in your database in the psql shell: with \dn
Example:
drupal6=# \dn
List of schemas
Name | Owner
--------------------+--------
bsn | drupal
cantor | drupal
information_schema | pgsql
pg_catalog | pgsql
pg_toast | pgsql
pjb2 | drupal
pjb3 | drupal
public | pgsql
...

3.1. in sites/www.mydomain.com/settings.php set:
$db_url = 'pgsql://username:password@localhost/databasename';
You must set THE SAME username in step 2 and in step 3.1

3.2. in sites/www.mydomain.com/settings.php set:
$db_prefix = 'schemaname.';
Note: use your actual schemaname with a trailing dot (.) !
You must use the same schemaname in step 2 and in step 3.2

DONE.

We are running this with around 6 drupal 6.11 sites and about 12
extra modules installed without problems.