limit

This page explains how to use the limit operator in APL.

The limit operator in Axiom Processing Language (APL) allows you to restrict the number of rows returned from a query. It is particularly useful when you want to see only a subset of results from large datasets, such as when debugging or previewing query outputs. The limit operator can help optimize performance and focus analysis by reducing the amount of data processed.

Use the limit operator when you want to return only the top rows from a dataset, especially in cases where the full result set is not necessary.

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, the equivalent to APL’s limit is the head command, which also returns the top rows of a dataset. The main difference is in the syntax.

Splunk example

| head 10

ANSI SQL users

In ANSI SQL, the LIMIT clause is equivalent to the limit operator in APL. The SQL LIMIT statement is placed at the end of a query, whereas in APL, the limit operator comes after the dataset reference.

SQL example

SELECT * FROM sample_http_logs LIMIT 10;

Usage

Syntax

| limit [N]

Parameters

• N: The maximum number of rows to return. This must be a non-negative integer.

Returns

The limit operator returns the top N rows from the input dataset. If fewer than N rows are available, all rows are returned.

Use case examples

Log analysis

In log analysis, you often want to view only the most recent entries, and limit can help narrow the focus on those rows.

Query

['sample-http-logs']
| limit 5

Run in Playground

Output

_time	req_duration_ms	id	status	uri	method	geo.city	geo.country
2024-10-17T12:00:00	200	123	200	/index.html	GET	New York	USA
2024-10-17T11:59:59	300	124	404	/notfound.html	GET	London	UK

This query limits the output to the first 5 rows from the ['sample-http-logs'] dataset, returning recent HTTP log entries.

List of related operators

• take: Similar to limit, but explicitly focuses on row sampling.
• top: Retrieves the top N rows sorted by a specific field.
• sample: Randomly samples N rows from the dataset.