COMMENT ON AGGREGATE FUNCTION

Adds, revises, or removes a comment on an aggregate function. Each object can have one comment. Comments are stored in the system table COMMENTS.

Syntax

COMMENT ON AGGREGATE FUNCTION [[database.]schema.]function (function‑args) IS { 'comment' | NULL };

Parameters

[database.]schema

Specifies a schema, by default public. If schema is any schema other than public, you must supply the schema name. For example:

myschema.thisDbObject

If you specify a database, it must be the current database.

function

The name of the aggregate function with which to associate the comment.

function‑args

The function arguments.

comment

Specifies the comment text to add. If a comment already exists for this function, this overwrites the previous one.

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

Superuser or object owner

Examples

The following example adds a comment to the APPROXIMATE_MEDIAN(x FLOAT) function:

=> COMMENT ON AGGREGATE FUNCTION APPROXIMATE_MEDIAN(x FLOAT) IS 'alias of APPROXIMATE_PERCENTILE with 0.5 as its parameter';

The following example removes a comment from the APPROXIMATE_MEDIAN(x FLOAT) function:

=> COMMENT ON AGGREGATE FUNCTION APPROXIMATE_MEDIAN(x FLOAT) IS NULL;