min_of

This page explains how to use the min_of function in APL.

Use the min_of function in APL to determine the minimum value among two or more scalar values. The function returns the smallest of its arguments, making it especially useful when you want to compare metrics, constants, or calculated expressions in queries.

You typically use min_of when you want to:

• Compare numeric or time-based values across multiple fields or constants.
• Apply conditional logic in summarization or filtering steps.
• Normalize or bound values when computing metrics.

Unlike aggregation functions such as min(), which work across rows in a group, min_of operates on values within a single row or context.

For users of other query languages

If you come from other query languages, this section explains how to adjust your existing queries to achieve the same results in APL.

Splunk SPL users

In Splunk, you often use the eval command with the min function to compare multiple values. APL’s min_of is similar, but used as a scalar function directly in expressions.

Splunk example

eval smallest=min(field1, field2)

ANSI SQL users

In SQL, you typically use LEAST() to find the smallest of multiple values. APL’s min_of is the equivalent of LEAST().

SQL example

SELECT LEAST(col1, col2, col3) AS min_val FROM table;

Usage

Syntax

min_of(Expr1, Expr2, ..., ExprN)

Parameters

The function takes a comma-separated list of expressions to compare. All values must be of the same type.

Returns

The function returns the smallest of the provided values. The type of the return value matches the type of the input arguments.

Use case example

You have two data points for the size of HTTP responses: header size and body size. You want to find the minimum of these two values for each event.

Query

['sample-http-logs']
| extend min_size = min_of(resp_header_size_bytes, resp_body_size_bytes)
| project _time, id, resp_header_size_bytes, resp_body_size_bytes, min_size

Run in Playground

Output

_time	id	resp_header_size_bytes	resp_body_size_bytes	min_size
May 15, 11:31:05	739b0433-39aa-4891-a5e0-3bde3cb40386	41 B	3,410 B	41
May 15, 11:31:05	3016c439-ea30-454b-858b-06f0a66f44b9	53 B	5,333 B	53
May 15, 11:31:05	b26b0a5c-bc73-4693-86ad-be9e0cc767d6	60 B	2,936 B	60
May 15, 11:31:05	8d939423-26ae-43f7-9927-13499e7cc7d3	60 B	2,896 B	60
May 15, 11:31:05	10c37b1a-5639-4c99-a232-c8295e3ce664	63 B	4,871 B	63
May 15, 11:31:05	4aa1821a-6906-4ede-9417-3097efb76b89	78 B	1,729 B	78
May 15, 11:31:05	6325de66-0033-4133-b2f3-99fa70f8c9c0	96 B	4,232 B	96