# DESCRIBE \<statement>

## Syntax

```sql
DESCRIBE statement;
```

## Description

This command provides details about the objects used by a `CREATE_RELATION`, `INSERT INTO`, or `CREATE AS SELECT` statement.

The statement is described only if the current role has the `USAGE` privilege on the [Database](/overview/core-concepts/databases.md), [Schema](/overview/core-concepts/databases.md#schema), [Store](/overview/core-concepts/store.md), and [Relation](/overview/core-concepts/databases.md#relation) used in the statement.

### Arguments <a href="#parameters" id="parameters"></a>

#### statement

Any of the executable statements including [CREATE STREAM](/reference/sql-syntax/ddl/create-stream.md), [CREATE CHANGELOG](/reference/sql-syntax/ddl/create-changelog.md), [CREATE STREAM AS SELECT](/reference/sql-syntax/query/create-stream-as.md), [CREATE CHANGELOG AS SELECT](/reference/sql-syntax/query/create-changelog-as.md), [CREATE MATERIALIZED VIEW AS](/reference/sql-syntax/query/materialized-view/create-materialized-view-as.md), [CREATE TABLE AS SELECT](/reference/sql-syntax/query/create-table-as.md).

<details>

<summary>Response Columns</summary>

* `type`: Provides the type of the statement being described.
* `info`: A key-value list of objects used within the statement and specific information about them:
  * `ddl`/`sink`: A new relation the statement creates to write to — or, respectively, an existing relation to which the statement writes new records.
    * Provides `fqn`, `type`, `db_name`, `schema_name`, `name`, and `store_name`. A `fqn` is in the format of `org.db.schema.relation`.
  * `Sources`: List of relations the statement uses for reading records.
    * Provides `fqn`, `type`, `db_name`, `schema_name`, `name`, and `store_name`.

</details>

## Examples

#### Describe a stream DDL statement

In this example, a `CREATE STREAM` statement returns a `ddl` field for the `pageviews` stream that would be created if the statement was executed:

```sh
demodb.public/demostore# DESCRIBE CREATE STREAM pageviews (viewtime BIGINT, userid VARCHAR, pageid VARCHAR) WITH ('value.format'='json', 'topic.partitions'='5', 'topic.replicas'='5');
+---------------+------------------------------------------+
|  Type         |  Info                                    |
+===============+==========================================+
| CREATE_STREAM | {"ddl":{"fqn":"d39511ce-c918-4637-9524-1 |
|               | 63183452274.demodb.public.pageviews","ty |
|               | pe":"STREAM","db_name":"demodb","schema_ |
|               | name":"public","name":"pageviews","store |
|               | _name":"demostore"}}                     |
+---------------+------------------------------------------+
```

#### Describe a CCAS filter statement

In this example, `pageviewscl` [Database](/overview/core-concepts/databases.md#changelog) is filtered and writes its result into `pageviewscl_6` changelog:

```sh
demodb.public/demostore# DESCRIBE CREATE CHANGELOG PAGEVIEWSCL_6 AS SELECT userid, pageid FROM PAGEVIEWSCL WHERE userid = 'User_6';
+---------------------+------------------------------------------+
|  Type               |  Info                                    |
+=====================+==========================================+
| CREATE_CHANGELOG_AS | {"ddl":{"fqn":"d39511ce-c918-4637-9524-1 |
|                     | 63183452274.demodb.public.pageviewscl_6" |
|                     | ,"type":"CHANGELOG","db_name":"demodb"," |
|                     | schema_name":"public","name":"pageviewsc |
|                     | l_6","store_name":"demostore"},"sources" |
|                     | :[{"fqn":"d39511ce-c918-4637-9524-163183 |
|                     | 452274.demodb.public.pageviewscl","type" |
|                     | :"CHANGELOG","db_name":"demodb","schema_ |
|                     | name":"public","name":"pageviewscl","sto |
|                     | re_name":"demostore"}]}                  |
+---------------------+------------------------------------------+

```

#### Describe a CSAS JOIN statement

In this example, the described statement joins the `pageviews` [Database](/overview/core-concepts/databases.md#stream) and `users1Changelog` changelog before filtering and writing its results into the `temporaljoin` stream:

```sh
demodb.public/demostore# DESCRIBE CREATE STREAM temporaljoin AS SELECT p.userid AS pvuid, u.userid, u.gender, p.pageid, u.interests[1] AS top_interest FROM pageviews p JOIN "users1Changelog" u ON u.userid = p.userid WHERE p.userid != 'User_5';
+------------------+------------------------------------------+
|  Type            |  Info                                    |
+==================+==========================================+
| CREATE_STREAM_AS | {"ddl":{"fqn":"d39511ce-c918-4637-9524-1 |
|                  | 63183452274.demodb.public.temporaljoin", |
|                  | "type":"STREAM","db_name":"demodb","sche |
|                  | ma_name":"public","name":"temporaljoin", |
|                  | "store_name":"demostore"},"sources":[{"f |
|                  | qn":"d39511ce-c918-4637-9524-16318345227 |
|                  | 4.demodb.public.pageviews","type":"STREA |
|                  | M","db_name":"demodb","schema_name":"pub |
|                  | lic","name":"pageviews","store_name":"de |
|                  | mostore"},{"fqn":"d39511ce-c918-4637-952 |
|                  | 4-163183452274.demodb.public.users1Chang |
|                  | elog","type":"CHANGELOG","db_name":"demo |
|                  | db","schema_name":"public","name":"users |
|                  | 1Changelog","store_name":"demostore"}]}  |
+------------------+------------------------------------------+
```

#### Describe an INSERT INTO statement

The example below shows that the statement filters the `pageviews` stream and writes its results into the existing relation called `pageviews_6` of type `stream`:

```sh
demodb.public/demostore# DESCRIBE INSERT INTO PAGEVIEWS_6 SELECT userid, pageid FROM PAGEVIEWS WHERE userid = 'User_6';
+-------------+------------------------------------------+
|  Type       |  Info                                    |
+=============+==========================================+
| INSERT_INTO | {"sink":{"fqn":"d39511ce-c918-4637-9524- |
|             | 163183452274.demodb.public.pageviews_6", |
|             | "type":"STREAM","db_name":"demodb","sche |
|             | ma_name":"public","name":"pageviews_6"," |
|             | store_name":"demostore"},"sources":[{"fq |
|             | n":"d39511ce-c918-4637-9524-163183452274 |
|             | .demodb.public.pageviews","type":"STREAM |
|             | ","db_name":"demodb","schema_name":"publ |
|             | ic","name":"pageviews","store_name":"dem |
|             | ostore"}]}                               |
+-------------+------------------------------------------+
```


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