Declaring an alias for the table

You can declare an alias for the table. The alias can reference the fully-qualified database object name of a local or remote table, view, or synonym.

The alias is a temporary name that is not registered in the system catalog of the database, and that persists only while the DELETE statement is running.

If the name that you declare as the alias is the keyword WHERE, you must use the AS keyword to clarify the syntax: 
DELETE stock AS where 
   WHERE manu_code = 
      (SELECT manu_code FROM where WHERE manu_code MATCHES 'H*');
Because where is a keyword of both the DELETE and SELECT statements, the previous example is not easy to read. The following example accesses a remote table without declaring an alias for the table:
DELETE overstock@cleveland:stock AS ocs 
   WHERE manu_code = 
      (SELECT manu_code FROM overstock@cleveland:stock 
       WHERE manu_code MATCHES 'H*');
;

The next example is logically equivalent to the previous DELETE statement, but simplifies the notation by declaring ocs as alias that references the same table in the subquery"
DELETE overstock@cleveland:stock AS ocs 
   WHERE manu_code = 
      (SELECT manu_code FROM ocs WHERE manu_code MATCHES 'H*');
;