2025 Changelog

#### New Feature[​](#new-feature-3 "Direct link to New Feature")

- You can now use NATS JetStream to consume messages by specifying the new settings of `nats_stream` and `nats_consumer` for the NATS engine. [#84799](https://github.com/ClickHouse/ClickHouse/pull/84799) ([Dmitry Novikov](https://github.com/dmitry-sles-novikov)).
- Added support for authentication and SSL in the `arrowFlight` table function. [#87120](https://github.com/ClickHouse/ClickHouse/pull/87120) ([Vitaly Baranov](https://github.com/vitlibar)).
- Add new parameter to `S3` table engine and `s3` table function named `storage_class_name` which allows to specify intelligent tiring supported by AWS. Supported both in key-value format and in positional (deprecated) format). [#87122](https://github.com/ClickHouse/ClickHouse/pull/87122) ([alesapin](https://github.com/alesapin)).
- `ALTER UPDATE` for Iceberg table engine. [#86059](https://github.com/ClickHouse/ClickHouse/pull/86059) ([scanhex12](https://github.com/scanhex12)).
- Add system table `iceberg_metadata_log` to retrieve Iceberg metadata files during SELECT statements. [#86152](https://github.com/ClickHouse/ClickHouse/pull/86152) ([scanhex12](https://github.com/scanhex12)).
- `Iceberg` and `DeltaLake` tables support custom disk configuration via storage level setting `disk`. [#86778](https://github.com/ClickHouse/ClickHouse/pull/86778) ([scanhex12](https://github.com/scanhex12)).
- Support Azure for data lakes disks. [#87173](https://github.com/ClickHouse/ClickHouse/pull/87173) ([scanhex12](https://github.com/scanhex12)).
- Support `Unity` catalog on top of Azure blob storage. [#80013](https://github.com/ClickHouse/ClickHouse/pull/80013) ([Smita Kulkarni](https://github.com/SmitaRKulkarni)).
- Support more formats (`ORC`, `Avro`) in `Iceberg` writes. This closes [#86179](https://github.com/ClickHouse/ClickHouse/issues/86179). [#87277](https://github.com/ClickHouse/ClickHouse/pull/87277) ([scanhex12](https://github.com/scanhex12)).
- Add a new system table `database_replicas` with information about database replicas. [#83408](https://github.com/ClickHouse/ClickHouse/pull/83408) ([Konstantin Morozov](https://github.com/k-morozov)).
- Added function `arrayExcept` that subtracts one array as a set from another. [#82368](https://github.com/ClickHouse/ClickHouse/pull/82368) ([Joanna Hulboj](https://github.com/jh0x)).
- Adds a new `system.aggregated_zookeeper_log` table. The table contains statistics (e.g. number of operations, average latency, errors) of ZooKeeper operations grouped by session id, parent path and operation type, and periodically flushed to disk. [#85102](https://github.com/ClickHouse/ClickHouse/pull/85102) [#87208](https://github.com/ClickHouse/ClickHouse/pull/87208) ([Miсhael Stetsyuk](https://github.com/mstetsyuk)).
- A new function, `isValidASCII`. Returns 1 if the input string or FixedString contains only ASCII bytes (0x00–0x7F) else 0. Closes [#85377](https://github.com/ClickHouse/ClickHouse/issues/85377). ... [#85786](https://github.com/ClickHouse/ClickHouse/pull/85786) ([rajat mohan](https://github.com/rajatmohan22)).
- Boolean settings can be specified without arguments, e.g., `SET use_query_cache;`, which is equivalent to setting it to true. [#85800](https://github.com/ClickHouse/ClickHouse/pull/85800) ([thraeka](https://github.com/thraeka)).
- New configuration options: `logger.startupLevel` & `logger.shutdownLevel` allow for overriding the log level during the startup & shutdown of Clickhouse respectively. [#85967](https://github.com/ClickHouse/ClickHouse/pull/85967) ([Lennard Eijsackers](https://github.com/Blokje5)).
- Aggregate functions `timeSeriesChangesToGrid` and `timeSeriesResetsToGrid`. Behaves similarly to `timeSeriesRateToGrid`, accepting parameters for start timestamp, end timestamp, step, and look back window, as well as two arguments for the timestamps and values, but requiring at least 1 sample per window instead of 2. Calculates a PromQL `changes`/`resets`, counting the number of times the sample value changes or decreases in the specified window for each timestamp in the time grid defined by the parameters. The return type is `Array(Nullable(Float64))`. [#86010](https://github.com/ClickHouse/ClickHouse/pull/86010) ([Stephen Chi](https://github.com/stephchi0)).
- Allows users to create temporary views with a similar syntax to temporary tables (`CREATE TEMPORARY VIEW`). [#86432](https://github.com/ClickHouse/ClickHouse/pull/86432) ([Aly Kafoury](https://github.com/AlyHKafoury)).
- Add warnings for CPU and memory usage to the `system.warnings` table. [#86838](https://github.com/ClickHouse/ClickHouse/pull/86838) ([Bharat Nallan](https://github.com/bharatnc)).
- Support the `oneof` indicator in `Protobuf` inputs. A special column may be used to indicate the presence of part of oneof. If a message contains [oneof](https://protobuf.dev/programming-guides/proto3/#oneof) and `input_format_protobuf_oneof_presence` is set, ClickHouse fills column that indicates which field of oneof was found. [#82885](https://github.com/ClickHouse/ClickHouse/pull/82885) ([Ilya Golshtein](https://github.com/ilejn)).
- Improve allocation profiling based on jemalloc's internal tooling. Global jemalloc profiler can now be enabled with config `jemalloc_enable_global_profiler`. Sampled global allocations and deallocations can be stored in `system.trace_log` under `JemallocSample` type by enabling config `jemalloc_collect_global_profile_samples_in_trace_log`. Jemalloc profiling can now be enabled for each query independently using setting `jemalloc_enable_profiler`. Storing samples in `system.trace_log` can be controlled per query using setting `jemalloc_collect_profile_samples_in_trace_log`. Update jemalloc to newer version. [#85438](https://github.com/ClickHouse/ClickHouse/pull/85438) ([Antonio Andelic](https://github.com/antonio2368)).
- A new setting to delete files on dropping Iceberg tables. This closes [#86211](https://github.com/ClickHouse/ClickHouse/issues/86211). [#86501](https://github.com/ClickHouse/ClickHouse/pull/86501) ([scanhex12](https://github.com/scanhex12)).

#### Experimental Feature[​](#experimental-feature-3 "Direct link to Experimental Feature")

- The inverted text index was reworked from scratch to be scalable for datasets that don't fit into RAM. [#86485](https://github.com/ClickHouse/ClickHouse/pull/86485) ([Anton Popov](https://github.com/CurtizJ)).
- Join reordering now uses statistics. The feature can be enabled by setting `allow_statistics_optimize = 1` and `query_plan_optimize_join_order_limit = 10`. [#86822](https://github.com/ClickHouse/ClickHouse/pull/86822) ([Han Fei](https://github.com/hanfei1991)).
- Support `alter table ... materialize statistics all` will materialize all the statistics of a table. [#87197](https://github.com/ClickHouse/ClickHouse/pull/87197) ([Han Fei](https://github.com/hanfei1991)).

#### Performance Improvement[​](#performance-improvement-3 "Direct link to Performance Improvement")