anchor.diff:      : CREATE (GLOBAL TEMPORARY)? TABLE tableName relationalTable
       ;
   
  +createIndex
  +    : CREATE (UNIQUE | BITMAP)? INDEX indexName ON (tableIndexClause_ | bitmapJoinIndexClause_)
  +    ;
  +
   alterTable
       : ALTER TABLE tableName (alterTableProperties | columnClauses | constraintClauses | alterExternalTable)?
       ;
   
  +// TODO hongjun throw exeption when alter index on oracle
  +alterIndex
  +    : ALTER INDEX indexName (RENAME TO indexName)?
  +    ;
  +
   dropTable
       : DROP TABLE tableName
  +    ;
  + 
  +dropIndex
  +    : DROP INDEX indexName
       ;
   
   truncateTable
  
positive.code:     : tableName alias? columnName (ASC | DESC)?
      ;
  
  dropIndex
      : DROP INDEX indexName
      ;
  
  // TODO hongjun throw exeption when alter index on oracle
  alterIndex
      : ALTER INDEX indexName (RENAME TO indexName)?
      ;
  
negative.code:     : ELEMENT? IS OF TYPE? LP_ ONLY? dataTypeName_ RP_ | NOT? SUBSTITUTABLE AT ALL LEVELS
      ;
  
  tableIndexClause_
      : tableName alias? LP_ indexExpr_ (COMMA_ indexExpr_)* RP_
      ;
  