Amazon Redshift will no longer support the creation of new Python UDFs starting Patch 198. Existing Python UDFs will continue to function until June 30, 2026. For more information, see the [ blog post ](https://amazonaws-china.com/blogs/big-data/amazon-redshift-python-user-defined-functions-will-reach-end-of-support-after-june-30-2026/). 

# PG\$1TABLE\$1DEF
<a name="r_PG_TABLE_DEF"></a>

Stores information about table columns.

PG\$1TABLE\$1DEF only returns information about tables that are visible to the user. If PG\$1TABLE\$1DEF does not return the expected results, verify that the [search\$1path](r_search_path.md) parameter is set correctly to include the relevant schemas.

You can use [SVV\$1TABLE\$1INFO](r_SVV_TABLE_INFO.md) to view more comprehensive information about a table, including data distribution skew, key distribution skew, table size, and statistics. 

## Table columns
<a name="r_PG_TABLE_DEF-table-columns2"></a>

[\[See the AWS documentation website for more details\]](http://docs.amazonaws.cn/en_us/redshift/latest/dg/r_PG_TABLE_DEF.html)

## Example
<a name="r_PG_TABLE_DEF-example2"></a>

The following example shows the compound sort key columns for the LINEORDER\$1COMPOUND table.

```
select "column", type, encoding, distkey, sortkey, "notnull" 
from pg_table_def
where tablename = 'lineorder_compound' 
and sortkey <> 0;

column       | type    | encoding | distkey | sortkey | notnull
-------------+---------+----------+---------+---------+--------
lo_orderkey  | integer | delta32k | false   |       1 | true   
lo_custkey   | integer | none     | false   |       2 | true   
lo_partkey   | integer | none     | true    |       3 | true   
lo_suppkey   | integer | delta32k | false   |       4 | true   
lo_orderdate | integer | delta    | false   |       5 | true   
(5 rows)
```

 The following example shows the interleaved sort key columns for the LINEORDER\$1INTERLEAVED table.

```
select "column", type, encoding, distkey, sortkey, "notnull" 
from pg_table_def
where tablename = 'lineorder_interleaved' 
and sortkey <> 0;

column       | type    | encoding | distkey | sortkey | notnull
-------------+---------+----------+---------+---------+--------
lo_orderkey  | integer | delta32k | false   |      -1 | true   
lo_custkey   | integer | none     | false   |       2 | true   
lo_partkey   | integer | none     | true    |      -3 | true   
lo_suppkey   | integer | delta32k | false   |       4 | true   
lo_orderdate | integer | delta    | false   |      -5 | true   
(5 rows)
```

PG\$1TABLE\$1DEF will only return information for tables in schemas that are included in the search path. For more information, see [search\$1path](r_search_path.md).

For example, suppose you create a new schema and a new table, then query PG\$1TABLE\$1DEF.

```
create schema demo;
create table demo.demotable (one int);
select * from pg_table_def where tablename = 'demotable';

schemaname|tablename|column| type | encoding | distkey | sortkey | notnull 
----------+---------+------+------+----------+---------+---------+--------
```

The query returns no rows for the new table. Examine the setting for `search_path`.

```
show search_path;

  search_path
---------------
 $user, public
(1 row)
```

Add the `demo` schema to the search path and run the query again.

```
set search_path to '$user', 'public', 'demo';

select * from pg_table_def where tablename = 'demotable';

schemaname| tablename |column|  type   | encoding |distkey|sortkey| notnull
----------+-----------+------+---------+----------+-------+-------+--------
demo      | demotable | one  | integer | none     | f     |     0 | f
(1 row)
```