Known issues v26.3

This release includes the following known issues and limitations. Where applicable, workarounds are included to help mitigate the impact. These issues are actively tracked and are planned for resolution in a future release.

• The PostgreSQL table engine connects only to the WarehousePG coordinator and doesn't engage WarehousePG's massively parallel processing (MPP) architecture. For bulk data movement, use INSERT INTO clickhouse_table SELECT * FROM warehousepg_linked_table to load data into a native ClickHouse MergeTree table.

• The Iceberg catalog integration is read-only. INSERT, UPDATE, and DELETE operations aren't supported. Use Spark, PyIceberg, or another Iceberg-compatible writer to create and populate Iceberg tables.