hadoop-hdds/docs/content/integration/Impala.md

---
title: Impala
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Starting with version 4.2.0, Apache Impala provides full support for querying data stored in Apache Ozone. To utilize this functionality, ensure that your Ozone version is 1.4.0 or later.

## Supported Access Protocols

Impala supports the following protocols for accessing Ozone data:

* ofs
* s3a

Note: The o3fs protocol is **NOT** supported by Impala.

## Supported Replication Types

Impala is compatible with Ozone buckets configured with either:

* RATIS (Replication)
* Erasure Coding

## Querying Ozone Data with Impala

Impala provides two approaches to interact with Ozone:

* Managed Tables
* External Tables

### Managed Tables

If the Hive Warehouse Directory is located in Ozone, you can execute Impala queries without any changes, treating the Ozone file system like HDFS. For example:

```sql
CREATE DATABASE d1;
```

```sql
CREATE TABLE t1 (x INT, s STRING);
```

The data will be stored under the Hive Warehouse Directory path in Ozone.

#### Specifying a Custom Ozone Path

You can create managed databases, tables, or partitions at a specific Ozone path using the `LOCATION` clause. Example:

```sql
CREATE DATABASE d1 LOCATION 'ofs://ozone1/vol1/bucket1/d1.db';
```

```sql
CREATE TABLE t1 LOCATION 'ofs://ozone1/vol1/bucket1/table1';
```

### External Tables

You can create an external table in Impala to query Ozone data. For example:

```sql
CREATE EXTERNAL TABLE external_table (
  id INT,
  name STRING
)
LOCATION 'ofs://ozone1/vol1/bucket1/table1';
```

* With external tables, the data is expected to be created and managed by another tool.
* Impala queries the data as-is.
* The metadata is stored under the external warehouse directory.
* Note: Dropping an external table in Impala does not delete the associated data.


## Using the S3A Protocol

In addition to ofs, Impala can access Ozone via the S3 Gateway using the S3A file system. For more details, refer to 
* The [S3 Protocol]({{< ref "interface/S3.md">}})
* The [Hadoop S3A](https://hadoop.apache.org/docs/current/hadoop-aws/tools/hadoop-aws/index.html) documentation.

For additional information, consult the Apache Impala User Documentation
[Using Impala with Apache Ozone Storage](https://impala.apache.org/docs/build/html/topics/impala_ozone.html).