DESCRIBE RELATION COLUMNS

Syntax

DESCRIBE [ RELATION | STREAM | CHANGELOG | MATERIALIZED VIEW ]
COLUMNS fully_qualified_relation_name;

Description

This provides the information about an existing Relation's columns in a Database's schema. This command can also be used to define a specific Relation type's columns. See LIST RELATIONS for a list of available Relations to describe.

Relations will only be visible if the current Role has USAGE privileges on the Database and Schema and SELECT or INSERT privilege on the Relation.

Arguments

fully_qualified_relation_name

This is the name of the Relation to describe its columns. For case-sensitive names, the name must be wrapped in double quotes; otherwise, the lowercase name will be used.

The Relation name may optionally be fully qualified in the format of <database_name>.<schema_name>.<relation_name> or <schema_name>.<relation_name>. If the Database or Schema name is not provided, then the current session's Database or Schema will be used (see USE).

Examples

Describe a Stream's columns

demodb.public/demostore# DESCRIBE RELATION COLUMNS pageviews;
+----------+---------+-----------+-------------+
|  Name    |  Type   |  Nullable |  Properties |
+==========+=========+===========+=============+
| viewtime | BIGINT  | true      | {}          |
+----------+---------+-----------+-------------+
| userid   | VARCHAR | true      | {}          |
+----------+---------+-----------+-------------+
| pageid   | VARCHAR | true      | {}          |
+----------+---------+-----------+-------------+

Describe a Stream's columns in a specific Database/Schema

The following describes the total_views Stream Relation columns in the demodb Database and analytics Schema, using its fully qualified Relation name:

demodb.public/demostore# DESCRIBE RELATION COLUMNS pageviews;
+----------+---------+-----------+-------------+
|  Name    |  Type   |  Nullable |  Properties |
+==========+=========+===========+=============+
| viewtime | BIGINT  | true      | {}          |
+----------+---------+-----------+-------------+
| userid   | VARCHAR | true      | {}          |
+----------+---------+-----------+-------------+
| pageid   | VARCHAR | true      | {}          |
+----------+---------+-----------+-------------+

Describe a Materialized View's columns

The following describes the columns for pvcount in the demodb Databae and public Schema:

demodb.public/demostore# DESCRIBE MATERIALIZED VIEW COLUMNS demodb."public".pvcount;
+-------------+---------+-----------+-------------+
|  Name       |  Type   |  Nullable |  Properties |
+=============+=========+===========+=============+
| page_name   | VARCHAR | true      | {}          |
+-------------+---------+-----------+-------------+
| pageid      | VARCHAR | true      | {}          |
+-------------+---------+-----------+-------------+
| cnt         | BIGINT  | false     | {}          |
+-------------+---------+-----------+-------------+

Describe a Changelog

The following describes the users_log Changelog in the current Database and Schema:

demodb.public/demostore# DESCRIBE CHANGELOG COLUMNS users_log;
+--------------+-----------------------+-----------+-------------+
|  Name        |  Type                 |  Nullable |  Properties |
+==============+=======================+===========+=============+
| registertime | BIGINT                | true      | {}          |
+--------------+-----------------------+-----------+-------------+
| userid       | VARCHAR               | true      | {}          |
+--------------+-----------------------+-----------+-------------+
| regionid     | VARCHAR               | true      | {}          |
+--------------+-----------------------+-----------+-------------+
| gender       | VARCHAR               | true      | {}          |
+--------------+-----------------------+-----------+-------------+
| interests    | ARRAY<VARCHAR>        | true      | {}          |
+--------------+-----------------------+-----------+-------------+
| contactinfo  | STRUCT <phone VARCHAR | true      | {}          |
|              | , city VARCHAR,       |           |             |
|              | "state" VARCHAR, zip  |           |             |
|              | code VARCHAR>         |           |             |
+--------------+-----------------------+-----------+-------------+

Describe a Table's columns

The following describes the columns for pv_agg Table in the current Database and Schema:

demodb.public/demostore# DESCRIBE RELATION COLUMNS pv_agg;
+-----------+---------+-----------+-------------+
|  Name     |  Type   |  Nullable |  Properties |
+===========+=========+===========+=============+
| userid    | VARCHAR | true      | {}          |
+-----------+---------+-----------+-------------+
| pagecount | BIGINT  | true      | {}          |
+-----------+---------+-----------+-------------+

Describe a Relation's columns with a case-sensitive name

The following describes the columns for Pageviews Stream Relation in the current demodb Database and public Schema:

demodb.public/demostore# DESCRIBE RELATION "Pageviews";
+----------+---------+-----------+-------------+
|  Name    |  Type   |  Nullable |  Properties |
+==========+=========+===========+=============+
| viewtime | BIGINT  | true      | {}          |
+----------+---------+-----------+-------------+
| userid   | VARCHAR | true      | {}          |
+----------+---------+-----------+-------------+
| pageid   | VARCHAR | true      | {}          |
+----------+---------+-----------+-------------+