
DESCRIBE OUTPUT
===============

Synopsis
--------

``` sql
DESCRIBE OUTPUT statement_name
```

Description
-----------

List the output columns of a prepared statement, including the column name (or alias), catalog, schema, table, type, type size in bytes, and a boolean indicating if the column is aliased.

Examples
--------

Prepare and describe a query with four output columns:

    PREPARE my_select1 FROM
    SELECT * FROM nation

``` sql
DESCRIBE OUTPUT my_select1;
```

``` 
Column Name | Catalog | Schema | Table  |  Type   | Type Size | Aliased
-------------+---------+--------+--------+---------+-----------+---------
nationkey   | tpch    | sf1    | nation | bigint  |         8 | false
name        | tpch    | sf1    | nation | varchar |         0 | false
regionkey   | tpch    | sf1    | nation | bigint  |         8 | false
comment     | tpch    | sf1    | nation | varchar |         0 | false
(4 rows)
```

Prepare and describe a query whose output columns are expressions:

    PREPARE my_select2 FROM
    SELECT count(*) as my_count, 1+2 FROM nation

``` sql
DESCRIBE OUTPUT my_select2;
```

``` 
Column Name | Catalog | Schema | Table |  Type  | Type Size | Aliased
-------------+---------+--------+-------+--------+-----------+---------
my_count    |         |        |       | bigint |         8 | true
_col1       |         |        |       | bigint |         8 | false
(2 rows)
```

Prepare and describe a row count query:

    PREPARE my_create FROM
    CREATE TABLE foo AS SELECT * FROM nation

``` sql
DESCRIBE OUTPUT my_create;
```

``` 
Column Name | Catalog | Schema | Table |  Type  | Type Size | Aliased
-------------+---------+--------+-------+--------+-----------+---------
rows        |         |        |       | bigint |         8 | false
(1 row)
```

See Also
--------

[PREPARE](./prepare.md)
