# Joining custom metadata with S3 metadata tables
<a name="metadata-tables-join-custom-metadata"></a>

You can analyze data across your Amazon managed metadata tables and customer (self-managed) metadata tables. By using a standard SQL `JOIN` operator, you can query data from these multiple sources.

The following example SQL query finds matching records between an Amazon managed journal table (`"journal"`) and a self-managed metadata table (`{{my_self_managed_metadata_table}}`). The query also filters information based on `CREATE` events, which indicate that a new object (or a new version of the object) was written to the bucket. (For more information, see the [S3 Metadata journal tables schema](metadata-tables-schema.md).)

```
SELECT *
FROM "s3tablescatalog/aws-s3"."b_{{general-purpose-bucket-name}}"."journal" a
JOIN "{{my_namespace}}"."{{my_self_managed_metadata_table}}" b
ON a.bucket = b.bucket AND a.key = b.key AND a.version_id = b.version_id
WHERE a.record_type = 'CREATE';
```

The following example SQL query finds matching records between an Amazon managed inventory table (`"inventory"`) and a self-managed metadata table (`{{my_self_managed_metadata_table}}`):

```
SELECT *
FROM "s3tablescatalog/aws-s3"."b_{{general-purpose-bucket-name}}"."inventory" a
JOIN "{{my_namespace}}"."{{my_self_managed_metadata_table}}" b
ON a.bucket = b.bucket AND a.key = b.key AND a.version_id = b.version_id;
```