alter_table_spec

alter_table_spec 
      ::= 
      ( ( "add" "(" ( new_column_list 
      | new_constraint_list ) ")" ) 
      | ( "modify" "(" modified_column_list ")" ) 
      | ( "drop" "constraint" "(" constraint_list ")" ) 
      | ( storage_parameter { storage_parameter } ) 
      | ( "allocate" "extent" { allocate_spec } ) 
      | ( "enable" enable_spec ) 
      | ( "disable" disable_spec ) 
      ) 

This rule is called by

alter_table