Dremio Support Advisory, Thursday, Jan 23, 2025
***Dremio Software v26 Breaking Changes***
Please be advised that Dremio Software v26, targeted to ship within the next 3 months, contains potential breaking changes which are proactively communicated to you via this announcement. Should you have any questions, please contact Dremio Technical Support.
Important notice:
Version 26 will not be available for the Dremio AWS Edition (AWSE) on the AWS Marketplace.
- Dremio has extended the support life of AWS Edition Version 25 until the End of Life date of January 31, 2026
- If you haven’t done so, please consult your Dremio Account Executive for the migrations Dremio provides to another supported Dremio platform.
Breaking changes:
| Product Area | Summary | Implications & Recommendations |
| Kubernetes Deployment | In v26, Dremio Enterprise for Kubernetes Deployments, we will be introducing a new Dremio Helm Chart distributed through Quay.io. Additionally, a license must be provided in order to run the enterprise v26 edition in Kubernetes. | Kubernetes-deployed customers will need to leverage the new Dremio Helm chart and will need to provide a license key in order for Dremio to start. |
| Datalake Sources | In v25.2, Dremio launched a preview connector to Snowflake’s hosted catalog service. In v26, this source was renamed from Polaris (Preview) to Snowflake Open Catalog to match Snowflake’s naming convention after donating Polaris to the Apache Foundation. | Previously created REST API commands that reference Polaris source type or parameters in the body will need to be updated to use the new nomenclature. For example, the type in the create source call would now be SNOWFLAKEOPENCATALOG instead of POLARIS . The parameters within the source would similarly need to be changed from polarisCatalogWarehouse to snowflakeOpenCatalogWarehouse, as an example. |
| DML operations |
When writing into Iceberg tables, some related support options won’t be taken into account, but specific Iceberg table properties. According to the Iceberg specification, the default values of these table properties might be different than the default (or actual) values of the support options. For example, the default compression codec of the created Parquet files in an Iceberg table will be “zstd” according to the specification of the Iceberg table property “write.parquet.compression-codec” instead of the previous dremio default value “snappy” of the support option “store.parquet.compression”. |
In case of the changing default values are not suitable for a specific table, the value can be changed by using the ALTER TABLE <table name> SET TBLPROPERTIES ( '<property_name>' = '<property_value>' [ , ... ] ) command. Please consult the Dremio documentation “Supported Properties of Apache Iceberg Tables” for the detailed list of the supported Iceberg table properties and their defaults. |
| Supported DataSources | Updated our Elasticsearch client library to version 8.14.2. Support for older Elasticsearch versions (before 7.x) has been discontinued. | Please ensure your Elasticsearch cluster runs version 7.x or higher to maintain compatibility. |
| Reflection Manager | Now customers are not able to configure the maximum number of max reflection refresh retry attempts through the UI. reflection.manager.max_reflection_refresh_retry_attempts replaces the old support key layout.refresh.max.attempts. | By removing the user-facing configuration for the maximum number of reflection retry attempts, most customers will use the default value and get the full coverage and benefit of the enhanced retry policy. |
| Acceleration Settings on the reflection summary page is removed. The deprecated support keys include reflection.auto.max, reflection.auto.agg.enable, reflection.auto.raw.enable. |
Limited impact on customers. Removing voting feature from the UI(Acceleration Settings on the reflection summary page) because it isn’t supported on SW and never supported in DC. |
|
| Enforced reflection count guardrail in SW so that now Dremio software customers cannot create new reflections if there are already 500 or more active reflections. | The reflection count guardrail is introduced to ensure the reflection manager's stability. | |
| reflection.manager.refresh_schedule_policy.enabled support key is removed, meaning the refresh schedule policy is always available. This key was causing technical debt and potential consistency issues. |
The support keys:
are enabled by default, so users get the full benefit of reflection manager optimizations. |
|
| reflection.manager.skip_drop_table_job_for_incremental_refresh support key is removed, and the optimization to skip the drop table job will now apply to all incremental refreshes. | ||
| reflection.manager.load_materialization_job.enabled support key is removed, so all materialization tables are registered synchronously when the refresh finishes. | ||
| The COMPACT MATERIALIZATION job has been deprecated since it was used to optimize non-Iceberg materializations. | As Dremio only supports Iceberg materializations starting v26, the support for non-iceberg materialization and related jobs is removed. | |
| Support for PDFS and non-Iceberg storage for reflections is deprecated as Dremio moves entirely to Iceberg for reflection physical storage. This change simplifies code and resolves technical debt from maintaining multiple storage paths. | Users upgrading from versions that support non-Iceberg reflections (Dremio v11-v25), should be aware that all reflections will now use Iceberg storage. The reflection on non-iceberg storage will be automatically refreshed to the iceberg format. | |
| The Arrow reflection cache has been deprecated and removed from APIs, system tables, and the UI. | Since Arrow caching for reflections is no longer used, you can safely ignore the arrow_cache column. If your workflows rely on Arrow caching, they must be updated to work without it. |
If you have further questions, please contact Dremio Support via the Support Portal.