Domain Prefix on pgSQL

This issue is to work on getting pgSQL to work fully with the Domain Prefix module. The rest of Domain Access should function on pgSQL fine.

Here are the features that work, and the issues that remain.

-- Table creation works.
-- Table data copying works.
-- Table dropping works.

However, the following issues make the above functions useless:

-- Copying table definitions (such as default values, NOT NULL)
does not work.
-- Creating indexes does not work.
-- Creating sequences (and copying sequence values when necessary)
does not work.

I did research these issues and, frankly, they are delaying the release of the
module. I would love to support these features fully, but I suspect that it
will have to wait for Drupal 6, when we can simply use the information
contained in schema files.

Most of the information needed to perform these functions is available in pgSQL's internal catalogs: http://www.postgresql.org/docs/8.2/interactive/catalogs.html

The trick is reading the data and writing queries appropriately. Note that phpPgAdmin doesn't allow for table copying, suggesting the complexity level of the task.

I should note also that we can't simply run *.install files to create these tables, since most core tables are inside system.install and cannot be separated. That's where SchemaAPI will help solve this issue.