COMMENT ON TABLE COLUMN
Adds, revises, or removes a table column comment. Each object can have one comment. Comments are stored in the system table COMMENTS
.
Syntax
COMMENT ON COLUMN [[database.]schema.]table.column IS {'comment' | NULL}
Parameters
[database.]schema
|
Specifies a schema, by default myschema.thisDbObject If you specify a database, it must be the current database. |
table.column
|
The name of the table and column with which to associate the comment. |
comment |
Specifies the comment text to add. If a comment already exists for this column, this comment overwrites the previous comment. Comments can be up to 8192 characters in length. If a comment exceeds that limitation, Vertica truncates the comment and alerts the user with a message. |
NULL
|
Removes an existing comment. |
Privileges
Non-superuser: object owner
Example
The following example adds a comment to the transaction_time
column in the store_sales_fact
table in the store
schema:
=> COMMENT ON COLUMN store.store_sales_fact.transaction_time IS 'GMT';
The following example removes a comment from the transaction_time
column in the store_sales_fact
table in the store
schema:
=> COMMENT ON COLUMN store.store_sales_fact.transaction_time IS NULL;