ALTER EXTERNAL TABLE

Description

Changes the definition of an existing external table.

Click here to navigate to the Greenplum documentation page for this syntax.

External tables are translated into regular tables.

Grammar Syntax

Greenplum provides the ability to create ALTER EXTERNAL TABLE with multiple actions, but Snowflake does not, that's why is translated to individual ALTER TABLES.

ALTER EXTERNAL TABLE <name> <action> [, ... ]

where action is one of:
  ADD [COLUMN] <new_column> <type>
  DROP [COLUMN] <column> [RESTRICT|CASCADE]
  ALTER [COLUMN] <column> TYPE <type>
  OWNER TO <new_owner>

Sample Source Patterns

Greenplum

ALTER EXTERNAL TABLE Table1 
ADD COLUMN column1 VARCHAR(20),
DROP COLUMN column2 RESTRICT,
ALTER COLUMN column3 TYPE VARCHAR(10),
OWNER TO new_owner;

Snowflake

--** MSC-WARNING - MSC-GP0001 - EXTERNAL TABLE TRANSLATED TO REGULAR TABLE **
ALTER TABLE Table1
ADD COLUMN column1 VARCHAR(20);
ALTER TABLE Table1
DROP COLUMN column2 RESTRICT;
ALTER TABLE Table1
ALTER COLUMN column3 TYPE VARCHAR(10);
-- ** MSC-WARNING - MSC-PG0000 - USER PRIVILEGES MUST BE HANDLED MANUALLY **
--ALTER EXTERNAL TABLE Table1
--OWNER TO new_owner
                  ;

Related EWIs

1. MSC-PG0000: User privileges must be handled manually.
2. MSC-GP0001: External table translated to regular table.