Services or capabilities described in Amazon Web Services documentation might vary by Region. To see the differences applicable to the China Regions, see Getting Started with Amazon Web Services in China (PDF).

Amazon Redshift will no longer support the use of Python UDFs after June 30, 2026. We will start enforcing it in phases. For more information on the details of Python end of life and migration options, see the blog post that was published on June 30, 2025.

SLICE_NUM Function

Returns an integer corresponding to the slice number in the cluster where the data for a row is located. SLICE_NUM takes no parameters.

Syntax

SLICE_NUM()

Return type

The SLICE_NUM function returns an integer.

Examples

The following example shows which slices contain data for the first ten EVENT rows in the EVENTS table:

select distinct eventid, slice_num() from event order by eventid limit 10;

 eventid | slice_num
---------+-----------
       1 |         1
       2 |         2
       3 |         3
       4 |         0
       5 |         1
       6 |         2
       7 |         3
       8 |         0
       9 |         1
      10 |         2
(10 rows)

The following example returns a code (10000) to show that a query without a FROM statement runs on the leader node:

select slice_num();
slice_num
-----------
10000
(1 row)