ALTER FOREIGN TABLE Syntax | VantageCloud Lake - ALTER FOREIGN TABLE Syntax - Teradata VantageCloud Lake

ALTER FOREIGN TABLE table_specification 
  [ , table_option [,...] ]
  [ , external_security_clause ] 
  [ column_option ]
  [ UPDATE update_specification ]
  [ MODIFY PARTITION BY ( [ COLUMN, ] partition_column_spec [,...] ) ]
  [ REFRESH SNAPSHOT_LOCATION ]

table_specification

[ database_name. | user_name. ] table_name

external_security_clause

EXTERNAL SECURITY [ { INVOKER | DEFINER } TRUSTED ]
  [ database_name.| user_name.]authorization_name

column_option

{ ADD { column change |
        (named_column_specification [,...]) INTO column_2 |
        [ COLUMN | ROW ] (named_column_specification [,...]) [ [NO] AUTO COMPRESS ] |
        [ COLUMN | ROW | SYSTEM ] (column) [ [NO] AUTO COMPRESS ]
  } |
  DROP column [ IDENTITY ] |
  RENAME column { AS | TO } new_name
}

update_specification

{ [ LOCATION (location_column) ]
  [ ENDPOINT ( location_column ) ]
  [ PATHPATTERN (path_pattern) ]
  [ MANIFEST [ ({ 'TRUE' | 'FALSE' }) ] ]
  [ ROWFORMAT [ (row_format) ] ] 
  [ STOREDAS [ ({ 'TEXTFILE' | 'PARQUET' }) ] ]
  [ STRIP_EXTERIOR_SPACES [ ({ 'TRUE' | 'FALSE' }) ] ]
  [ STRIP_ENCLOSING_CHAR [ ({ 'NONE' | '"' }) ] ]
  [ SNAPSHOT_LOCATION('manifest_file_path') ]
}

change

{ nameless_column_specification [ INTO column_2 ] |
  data_type_attributes |
  [ CONSTRAINT constraint_name ] column_constraint |
  NULL |
  security_constraint_column_declaration |
}

named_column_specification

column data_type_declaration [ data_type_attributes ]

nameless_column_specification

data_type_declaration [ data_type_attributes ]

partition_column_spec

partition_column_name partition_column_data_type

The total number of partition columns cannot exceed 20.

The resulting total number of columns cannot exceed 2048.