2025 Changelog

- Async logging: Make limits tuneable and add introspection. [#85105](https://github.com/ClickHouse/ClickHouse/pull/85105) ([Raúl Marín](https://github.com/Algunenano)).
- Collect all removed objects to execute single object storage remove operation. [#85316](https://github.com/ClickHouse/ClickHouse/pull/85316) ([Mikhail Artemenko](https://github.com/Michicosun)).
- Iceberg's current implementation of positional delete files keeps all data in RAM. This can be quite expensive if the positional delete files are large, which is often the case. My implementation keeps only the last row-group of Parquet delete files in RAM, which is significantly cheaper. [#85329](https://github.com/ClickHouse/ClickHouse/pull/85329) ([Konstantin Vedernikov](https://github.com/scanhex12)).
- chdig: fix leftovers on the screen, fix crash after edit query in editor, search in `path` for `editor`, update to [25.8.1](https://github.com/azat/chdig/releases/tag/v25.8.1). [#85341](https://github.com/ClickHouse/ClickHouse/pull/85341) ([Azat Khuzhin](https://github.com/azat)).
- Add missing `partition_columns_in_data_file` to azure configuration. [#85373](https://github.com/ClickHouse/ClickHouse/pull/85373) ([Arthur Passos](https://github.com/arthurpassos)).
- Allow zero step in functions `timeSeries*ToGrid` This is part of [#75036](https://github.com/ClickHouse/ClickHouse/pull/75036). [#85390](https://github.com/ClickHouse/ClickHouse/pull/85390) ([Vitaly Baranov](https://github.com/vitlibar)).
- Added show\_data\_lake\_catalogs\_in\_system\_tables flag to manage adding data lake tables in system.tables. Resolves [#85384](https://github.com/ClickHouse/ClickHouse/issues/85384). [#85411](https://github.com/ClickHouse/ClickHouse/pull/85411) ([Smita Kulkarni](https://github.com/SmitaRKulkarni)).
- Added support for macro expansion in `remote_fs_zero_copy_zookeeper_path`. [#85437](https://github.com/ClickHouse/ClickHouse/pull/85437) ([Mikhail Koviazin](https://github.com/mkmkme)).
- AI in clickhouse-client will look slightly better. [#85447](https://github.com/ClickHouse/ClickHouse/pull/85447) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
- Enable trace\_log.symbolize for old deployments by default. [#85456](https://github.com/ClickHouse/ClickHouse/pull/85456) ([Azat Khuzhin](https://github.com/azat)).
- Support resolution of more cases for compound identifiers. Particularly, it improves the compatibility of `ARRAY JOIN` with the old analyzer. Introduce a new setting `analyzer_compatibility_allow_compound_identifiers_in_unflatten_nested` to keep the old behaviour. [#85492](https://github.com/ClickHouse/ClickHouse/pull/85492) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
- Ignore UNKNOWN\_DATABASE while obtaining table columns sizes for system.columns. [#85632](https://github.com/ClickHouse/ClickHouse/pull/85632) ([Azat Khuzhin](https://github.com/azat)).
- Added a limit (table setting `max_uncompressed_bytes_in_patches`) for total uncompressed bytes in patch parts. It prevents significant slowdowns of SELECT queries after lightweight updates and prevents possible misuse of lightweight updates. [#85641](https://github.com/ClickHouse/ClickHouse/pull/85641) ([Anton Popov](https://github.com/CurtizJ)).
- Add a `parameter` column to `system.grants` to determine source type for `GRANT READ/WRITE` and the table engine for `GRANT TABLE ENGINE`. [#85643](https://github.com/ClickHouse/ClickHouse/pull/85643) ([MikhailBurdukov](https://github.com/MikhailBurdukov)).
- Fix parsing of a trailing comma in columns of the CREATE DICTIONARY query after a column with parameters, for example, Decimal(8). Closes [#85586](https://github.com/ClickHouse/ClickHouse/issues/85586). [#85653](https://github.com/ClickHouse/ClickHouse/pull/85653) ([Nikolay Degterinsky](https://github.com/evillique)).
- Support inner arrays for the function `nested`. [#85719](https://github.com/ClickHouse/ClickHouse/pull/85719) ([Nikolai Kochetov](https://github.com/KochetovNicolai)).
- All the allocations done by external libraries are now visible to ClickHouse's memory tracker and accounted properly. This may result in "increased" reported memory usage for certain queries or failures with `MEMORY_LIMIT_EXCEEDED`. [#84082](https://github.com/ClickHouse/ClickHouse/pull/84082) ([Nikita Mikhaylov](https://github.com/nikitamikhaylov)).