/**
  * Drop tables in old_schema no longer defined in new_schema
  * 
  * @param type $ofs
  * @param type $old_schema
  * @param type $new_schema
  * @param type $old_table
  * @param type $new_table
  */
 public static function drop_tables($ofs, $old_schema, $new_schema, $old_table = null, $new_table = null)
 {
     if ($old_schema != null && $new_schema != null) {
         foreach (dbx::get_tables($old_schema) as $table) {
             // if old table was defined
             if ($old_table != null) {
                 // is this the right old table?
                 if (strcasecmp($table['name'], $old_table['name']) != 0) {
                     continue;
                 }
             }
             // does the new schema contain the old table?
             if (!pgsql8_schema::contains_table($new_schema, $table['name'])) {
                 // if the table was renamed, don't drop it
                 if (!dbsteward::$ignore_oldnames && pgsql8_schema::table_formerly_known_as(dbsteward::$new_database, $new_schema, $table, $reformed_schema, $reformed_table)) {
                     $old_table_name = pgsql8::get_quoted_schema_name($new_schema['name']) . '.' . pgsql8::get_quoted_table_name($table['name']);
                     $reformed_table_name = pgsql8::get_quoted_schema_name($reformed_schema['name']) . '.' . pgsql8::get_quoted_table_name($reformed_table['name']);
                     $ofs->write("-- DROP TABLE {$old_table_name} omitted: new table {$reformed_table_name} indicates it is her replacement\n");
                 } else {
                     $ofs->write(pgsql8_table::get_drop_sql($old_schema, $table) . "\n");
                 }
             }
         }
     }
 }