Checks if an index exists in the given table.
$table: The name of the table in drupal (no prefixing).
$name: The name of the index in drupal (no prefixing).
TRUE if the given index exists, otherwise FALSE.
Overrides DatabaseSchema::indexExists
public function indexExists($table, $name) {
// Details http://www.postgresql.org/docs/8.3/interactive/view-pg-indexes.html
$index_name = '{' . $table . '}_' . $name . '_idx';
return (bool) $this->connection
->query("SELECT 1 FROM pg_indexes WHERE indexname = '{$index_name}'")
->fetchField();
}