In brief: CrateDB 4.0.2 is the most resilient version yet. It supports more SQL than ever, interoperates with even more PostgreSQL tools, and offers new options for working with time-series data. In addition, the user interface is slimmer and cleaner than before.
Improved window functions
We continue to work on features that make it easy to work with time-series data. Specifically, in this release, we have improved the options for specifying a frame for window functions.
Moved discovery to Zen2
To stay in sync with Elasticsearch, we have moved to Zen2, which improves CrateDB's clustering and node discovery. (Make sure to check your configuration for any necessary changes before upgrading.)
Improved PostgreSQL interoperability
With each release, we’re getting closer to full compatibility with the PostgreSQL dialect of SQL. In this release we have synced data types names, synced timestamp format, added the pg_catalog schema with its associated tables, and added functions that some tools require when connecting.
Improved ANSI SQL compliance
We've also improved our ANSI SQL compliance by adding support for the default clause in the CREATE TABLE statement, along with some additional changes.
Improved access controls
We have improved access control by introducing a dedicated privilege type for administrative tasks. In addition, masking for sensitive information has been added to improve security when handling Azure and AWS credentials.
Improved resiliency
We now expose_seq_no and _primary_term, which can be used for optimistic concurrency control. In addition, we've implemented a wealth of additional resiliency fixes, including support for Azure storage repositories.
We have removed the Elasticsearch REST API and the ingestion framework (including the MQTT endpoint). And, we’ve dropped support for the USR2 signal.
This release also includes minor fixups and improvements. Read the release notes for more information.