What's new and changed in Db2 Warehouse

IBM Cloud Pak® for Data Version 5.2.0

A new version of Db2 Warehouse was released in June 2025.

This release includes the following changes:

New features

This release of Db2 Warehouse includes the following features:

Take advantage of the improved efficiency, simplicity, and reliability of IBM Db2 12.1

Now when you install the Db2 Warehouse service on IBM® Software Hub, you are installing IBM Db2 12.1.

Db2 12.1 is a major release of IBM's Db2 database management system that focuses on AI-powered query optimization, security and manageability enhancements, and cloud object storage capabilities. Db2 12.1 includes a number of new and improved capabilities, including the following highlights:

• You can now use the AI-enhanced query optimizer to gain key improvements to functions of the optimizer that are suited to using AI techniques, such as estimating the number of rows that are processed by an access plan operator, known as the cardinality estimate. Use the improved estimate to more accurately determine the cost of that operator.
• You can now use a simplified edition of Db2 called IBM Db2 Starter Edition to get easier access to core data management capabilities for new applications and services.
• You can now improve the performance of insert operations by running bulk insert operations for Snowflake data sources in a Db2 Federation ODBC wrapper.
• You can now insert large object (LOB) values from optimized data sources into same-type columns in Db2 federated database tables.

For more information about these features and other enhancements in Db2 12.1, see What's new in Db2 12.1 in the IBM Db2 documentation.

Use the Db2uInstance custom resource (CR) to deploy new databases

You can now use the new Db2uInstance custom resource to deploy your Db2 Warehouse databases. The new CR has dedicated multiple logical node (MLN) volume support that aligns with the shared-nothing architecture of Db2 Warehouse. It also provides a significant performance increase on cloud platforms such as Amazon Web Services (AWS) and Azure. All new deployments will be on the new CRD, Db2uInstance. Existing deployments will stay on Db2uCluster.

Configure Db2 Warehouse to use Cloud Pak for Data backup and restore by using a custom Velero plugin

You must now use the custom Velero plugin, db2u-velero-plugin, in the DataProtectionApplication (DPA) to enable Cloud Pak for Data Backup and Restore (CPDBR) for Db2 Warehouse service instances. The plugin simplifies the backup and restore operation for all Kubernetes resources belonging to a Db2 Warehouse instance.

Updates

The following updates were introduced in this release:

• The number of Units of work (UOWs) that can be processed before an offline REORG TABLE operation is required is increased from 3 to 31.
• Five new fields are added to the history file entry. In addition, the maximum size of the COMMENT field is increased from 30 characters to 254 characters.

For a full list of enhancements and changes introduced in Db2 12.1, see What's new in Db2 12.1 in the IBM Db2 documentation.

Issues fixed in this release

The following issues were fixed in this release:

Db2 database is stuck when upgrading

• Issue: Db2 databases upgrading from version 5.0.3 to version 5.1.0 can get stuck at InProgress state.

Deprecated features

The following features were deprecated in this release:

Db2uCluster

The Db2uCluster custom resource has been deprecated and will be removed in a future release. To avoid future compatibility errors, migrate your existing databases from Db2uCluster to Db2uInstance. To migrate, complete a backup of your Db2uCluster database and then restore to a new Db2uInstance database. For more information, see Backing up a database and Restoring a database.