[Postgres] GROUP BY uses field names instead of aliases

From the Postgres manual (at the bottom in the 'Namespace Available to GROUP BY and ORDER BY' section):

PostgreSQL also allows [GROUP BY] to specify arbitrary expressions. Note that names appearing in an expression will always be taken as input-column names, not as result-column names.

The problem with this is that Views 2 builds its queries with the alias of the base table's unique ID being the same as the field name. For example: a View with a base table of {users} will include users.uid AS uid in its SELECT statement. Instead of doing this, Views should generate an alias with the same form of other fields, table_field. For example: users.uid AS users_uid.

To reproduce, using a clean checkout of Drupal 6/Views 2.6:

1. Ensure you Drupal/Views are setup to use a Postgres database ;)
2. import the following View:
   
   <?php
$view = new view;
$view->name = 'postgres_test_02';
$view->description = '';
$view->tag = '';
$view->view_php = '';
$view->base_table = 'node';
$view->is_cacheable = FALSE;
$view->api_version = 2;
$view->disabled = FALSE; /* Edit this to true to make a default view disabled initially */
$handler = $view->new_display('default', 'Defaults', 'default');
$handler->override_option('fields', array(
  'nid' => array(
    'label' => 'Nid',
    'alter' => array(
      'alter_text' => 0,
      'text' => '',
      'make_link' => 0,
      'path' => '',
      'link_class' => '',
      'alt' => '',
      'prefix' => '',
      'suffix' => '',
      'help' => '',
      'trim' => 0,
      'max_length' => '',
      'word_boundary' => 1,
      'ellipsis' => 1,
      'strip_tags' => 0,
      'html' => 0,
    ),
    'link_to_node' => 0,
    'exclude' => 0,
    'id' => 'nid',
    'table' => 'node',
    'field' => 'nid',
    'relationship' => 'nid',
  ),
  'body' => array(
    'label' => 'Body',
    'alter' => array(
      'alter_text' => 0,
      'text' => '',
      'make_link' => 0,
      'path' => '',
      'link_class' => '',
      'alt' => '',
      'prefix' => '',
      'suffix' => '',
      'help' => '',
      'trim' => 0,
      'max_length' => '',
      'word_boundary' => 1,
      'ellipsis' => 1,
      'strip_tags' => 0,
      'html' => 0,
    ),
    'exclude' => 0,
    'id' => 'body',
    'table' => 'node_revisions',
    'field' => 'body',
    'relationship' => 'none',
  ),
));
$handler->override_option('filters', array(
  'keys' => array(
    'operator' => 'optional',
    'value' => '',
    'group' => '0',
    'exposed' => TRUE,
    'expose' => array(
      'use_operator' => 0,
      'operator' => 'keys_op',
      'identifier' => 'keys',
      'label' => 'Search: Search Terms',
      'optional' => 1,
      'remember' => 0,
    ),
    'id' => 'keys',
    'table' => 'search_index',
    'field' => 'keys',
    'relationship' => 'none',
  ),
));
$handler->override_option('access', array(
  'type' => 'none',
));
$handler->override_option('cache', array(
  'type' => 'none',
));
$handler->override_option('distinct', 0);
$handler->override_option('style_plugin', 'table');
$handler->override_option('style_options', array(
  'grouping' => 'nid',
  'override' => 1,
  'sticky' => 0,
  'order' => 'asc',
  'columns' => array(
    'nid' => 'nid',
    'name' => 'name',
    'name_1' => 'name_1',
    'body' => 'body',
    'last_comment_name' => 'last_comment_name',
  ),
  'info' => array(
    'nid' => array(
      'sortable' => 0,
      'separator' => '',
    ),
    'name' => array(
      'sortable' => 0,
      'separator' => '',
    ),
    'name_1' => array(
      'sortable' => 0,
      'separator' => '',
    ),
    'body' => array(
      'separator' => '',
    ),
    'last_comment_name' => array(
      'sortable' => 0,
      'separator' => '',
    ),
  ),
  'default' => '-1',
));
$handler->override_option('row_options', array(
  'inline' => array(),
  'separator' => '',
));
?>
3. Save and go back to the Views list, select 'Edit' on 'postgres_test_02'
4. Press 'Preview' on the edit page
5. Enter some text into the search box, 'test' will do
6. Press 'Apply'
7. See this error:
   
   warning: pg_query() [function.pg-query]: Query failed: ERROR: column reference "nid" is ambiguous LINE 10: GROUP BY search_index.sid, nid, node_revisions_body, node_r... ^ in /home/liam/public_html/drupal6/includes/database.pgsql.inc on line 139.

The SQL generated by Views is:

Notice the first line: SELECT node.nid AS nid, then where Postgres gets confused because it believes 'nid' refers to the field, and finds two of them: GROUP BY [...] nid, [...]