> For the complete documentation index, see [llms.txt](https://docs.lenses.io/latest/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.lenses.io/latest/user-guide/6.2-user-guide/using/using-sql-to-query-kafka/limit-and-sampling.md).

# Limit & Sampling

Understand using limits and sampling when querying Kafka topic data with Lenses SQL Snapshot concepts engine for Apache Kafka

### Limit the output

Use `LIMIT` to limit output records. Use `max.size` to limit the amount of Kafka data scanned:

* `LIMIT` limits returned records.
* `max.size` limits Kafka data scanned, expressed as bytes.

```sql
-- Return at most one record.
SELECT *
FROM groceries
LIMIT 1;

-- Scan at most 1 MB of Kafka data.
SET max.size = '1m';

-- This cap can stop the query before LIMIT finds enough matching records.
SELECT *
FROM groceries;
```

`max.size` is not a memory allocation. It does not set the number of returned records.

### Set a time limit for a query

To restrict the time to run the query, use `SET max.query.time`:

{% code overflow="wrap" %}

```sql
SET  max.query.time = '1h';

SELECT ...
FROM table
LIMIT 1000
```

{% endcode %}

### Sampling data

To sample data and discard the first rows:

```sql
SELECT *
FROM groceries
LIMIT 1,2
```

This statement instructs Lenses to skip the first record matched and then sample the next two.


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