December 2025 newsletter

The December 2025 ClickHouse newsletter covers various updates, including a new Postgres extension for querying ClickHouse, cost-performance analyses of major cloud data warehouses, and a year-in-review for Postgres CDC. It highlights community member Zjan Carlo Turla's contributions to Canva's observability infrastructure and outlines upcoming global events, such as virtual training sessions and meetups in different regions. The newsletter also announces new self-paced learning paths, offering free ClickHouse certification until the end of 2025. Notable software updates include ClickHouse's 25.11 release, featuring enhancements like projections as secondary indices and optimized GROUP BY operations. It introduces pg_clickhouse, a PostgreSQL extension for enhanced query performance, and discusses multi-cloud cost analytics with ClickHouse. Additional insights are provided on optimizing ClickHouse for specific data types, setting up a local dbt environment, and using ClickHouse for security applications such as Tempesta FW's L7 DDoS mitigation.