External Hive Metastore

In case that you already have a Hive Metastore containing table definitions you want to access from the Denodo Embedded MPP, you can use that Hive Metastore as an external Metastore.

To do this, you can manually define a new catalog by creating the properties file in presto/conf/catalog/, e.g., presto/conf/catalog/ The file name, external_hivems, would be the catalog name.

To create the new catalog properties file, you can copy one of the catalogs shipped by default, depending on the files or tables you want to read:

  • copy the for accessing Hive tables over Parquet files.

  • copy the for accessing Delta Lake tables.

  • copy the for accessing Iceberg tables.

Then, fill in the hive.metastore.uri property with the URI of the external Hive Metastore.

Typically, you will have to add the hdfs-site.xml and the core-site.xml files to presto/conf/catalog and reference them in the hive.config.resources property.


# Bulk Data Load

# Avoids exceptions in partitioned tables


If the external Hive Metastore uses Kerberos authentication, you will need to configure additional properties in the catalog properties file:

Kerberos configuration in

This way the Embedded MPP connects to the Hive Metastore as the Kerberos principal hive.metastore.client.principal, using the keytab hive.metastore.client.keytab, and verifies that the identity of the Hive Metastore matches hive.metastore.service.principal.

You need to place the keytab file in the presto/secrets folder. You also need to place the krb5.conf in the presto/conf/catalog/ folder. And add the following configuration property to the values.yaml:

krb5.conf configuration
    additionalJVMConfig: [

If additionally, the Embedded MPP must authenticate to HDFS using Kerberos, you will need to configure additional properties in the catalog properties file:

HDFS Kerberos configuration in

This way the Embedded MPP connects to HDFS as the Kerberos principal hive.hdfs.presto.principal, using the keytab hive.hdfs.presto.keytab.

You need to place the keytab file in the presto/secrets folder.

If you use the same principal for both hive.metastore.client.principal and hive.hdfs.presto.principal make sure the principal has also access to HDFS, not just Hive Metastore, otherwise you will get a Permission denied error.

If is required by the Hadoop Cluster then one more property must be added to the catalog properties file:

Enable HDFS wire encryption in

You can find more information in Hive Security Configuration — Kerberos Support.

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