# Managing queries

### Termination Control <a href="#termination-control" id="termination-control"></a>

```sql
SELECT * FROM topicA WHERE _key.deviceId=123 LIMIT 10
```

Adding a **LIMIT 10** in the SQL query will result in the SQL terminating early, as soon as 10 x messages have been discovered. It’s not a perfect solution as we might never find 10 x messages, and thus perform a full scan.

You can also set a maximum query or idle time:

```sql
SET max.query.time = 30s;
```

or max idle time, the idea is that there is no reason to keep polling if we have exhausted the entire topic:

```sql
SET max.idle.time = 5s;
```

or a maximum amount of data to read from Kafka. This controls how much data to read from Kafka **NOT** the required memory.

```sql
SET max.size = 1M;
```

### Recent queries <a href="#recent-queries" id="recent-queries"></a>

Recent queries are displayed, but only for the current session, they are not currently retained.

Click on the play button to run a previous query. If a query is already running, you will be asked if you want to stop it first.

**View All queries**

```sql
SHOW ALL QUERIES
```

**View Running queries**

You can see all running queries by Lenses users using SQL:

```
SHOW QUERIES
```

### Kill Running queries <a href="#kill-running-queries" id="kill-running-queries"></a>

You can force stop a query by another user using SQL:

```sql
KILL QUERY <id>
```

### Concurrent queries limit <a href="#concurrent-queries-limit" id="concurrent-queries-limit"></a>

Starting with 6.1.3 version, there's a global limit on concurrent queries, as well as a limit per user. They can be set via the [agent configuration](/latest/deployment/configuration/agent/overview.md):

```properties
lenses.sql.settings.max.concurrent.queries=200
lenses.sql.settings.max.concurrent.queries.per.user=2
```


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://docs.lenses.io/latest/user-guide/using/using-sql-to-query-kafka/managing-queries.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.