2025 Changelog

- In AzureBlobStorage, for native copy we compare authentication methods, during which if we get an exception, updated the code to fallback to read and copy (i.e. non native copy). [#82693](https://github.com/ClickHouse/ClickHouse/pull/82693) ([Smita Kulkarni](https://github.com/SmitaRKulkarni)).
- Fix deserialization of `groupArraySample`/`groupArrayLast` in case of empty elements (deserialization could skip part of the binary if the input was empty, this can lead to corruption during data read and UNKNOWN\_PACKET\_FROM\_SERVER in TCP protocol). This does not affect numbers and date time types. [#82763](https://github.com/ClickHouse/ClickHouse/pull/82763) ([Pedro Ferreira](https://github.com/PedroTadim)).
- Fix backup of an empty `Memory` table, causing the backup restore to fail with with `BACKUP_ENTRY_NOT_FOUND` error. [#82791](https://github.com/ClickHouse/ClickHouse/pull/82791) ([Julia Kartseva](https://github.com/jkartseva)).
- Fix exception safety in union/intersect/except\_default\_mode rewrite. Closes [#82664](https://github.com/ClickHouse/ClickHouse/issues/82664). [#82820](https://github.com/ClickHouse/ClickHouse/pull/82820) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
- Keep track of the number of async tables loading jobs. If there are some running jobs, do not update `tail_ptr` in `TransactionLog::removeOldEntries`. [#82824](https://github.com/ClickHouse/ClickHouse/pull/82824) ([Tuan Pham Anh](https://github.com/tuanpach)).
- Fix data races in Iceberg. [#82841](https://github.com/ClickHouse/ClickHouse/pull/82841) ([Azat Khuzhin](https://github.com/azat)).
- Setting `use_skip_indexes_if_final_exact_mode` optimization (introduced in 25.6) could fail to select a relevant candidate range depending upon `MergeTree` engine settings / data distribution. That has been resolved now. [#82879](https://github.com/ClickHouse/ClickHouse/pull/82879) ([Shankar Iyer](https://github.com/shankar-iyer)).
- Set salt for auth data when parsing from AST with type SCRAM\_SHA256\_PASSWORD. [#82888](https://github.com/ClickHouse/ClickHouse/pull/82888) ([Tuan Pham Anh](https://github.com/tuanpach)).
- When using a non-caching Database implementation, the metadata of the corresponding table is deleted after the columns are returned and the reference is invalidated. [#82939](https://github.com/ClickHouse/ClickHouse/pull/82939) ([buyval01](https://github.com/buyval01)).
- Fix filter modification for queries with a JOIN expression with a table with storage `Merge`. Fixes [#82092](https://github.com/ClickHouse/ClickHouse/issues/82092). [#82950](https://github.com/ClickHouse/ClickHouse/pull/82950) ([Dmitry Novik](https://github.com/novikd)).
- Fix LOGICAL\_ERROR in QueryMetricLog: Mutex cannot be NULL. [#82979](https://github.com/ClickHouse/ClickHouse/pull/82979) ([Pablo Marcos](https://github.com/pamarcos)).
- Fixed incorrect output of function `formatDateTime` when formatter `%f` is used together with variable-size formatters (e.g. `%M`). [#83020](https://github.com/ClickHouse/ClickHouse/pull/83020) ([Robert Schulze](https://github.com/rschu1ze)).
- Fix performance degradation with the enabled analyzer when secondary queries always read all columns from the VIEWs. Fixes [#81718](https://github.com/ClickHouse/ClickHouse/issues/81718). [#83036](https://github.com/ClickHouse/ClickHouse/pull/83036) ([Dmitry Novik](https://github.com/novikd)).
- Fix misleading error message when restoring a backup on a read-only disk. [#83051](https://github.com/ClickHouse/ClickHouse/pull/83051) ([Julia Kartseva](https://github.com/jkartseva)).
- Do not check for cyclic dependencies on create table with no dependencies. It fixes performance degradation of the use cases with creation of thousands of tables that was introduced in <https://github.com/ClickHouse/ClickHouse/pull/65405>. [#83077](https://github.com/ClickHouse/ClickHouse/pull/83077) ([Pavel Kruglov](https://github.com/Avogar)).
- Fixes issue with implicit reading of negative Time values into the table and make the docs not confusing. [#83091](https://github.com/ClickHouse/ClickHouse/pull/83091) ([Yarik Briukhovetskyi](https://github.com/yariks5s)).
- Do not use unrelated parts of a shared dictionary in the `lowCardinalityKeys` function. [#83118](https://github.com/ClickHouse/ClickHouse/pull/83118) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
- Fix the regression in use of subcolumns with Materialized Views. This fixes: [#82784](https://github.com/ClickHouse/ClickHouse/issues/82784). [#83221](https://github.com/ClickHouse/ClickHouse/pull/83221) ([Nikita Mikhaylov](https://github.com/nikitamikhaylov)).
- Fix crash in client due to connection left in disconnected state after bad INSERT. [#83253](https://github.com/ClickHouse/ClickHouse/pull/83253) ([Azat Khuzhin](https://github.com/azat)).
- Fix crash when calculating the size of a block with empty columns. [#83271](https://github.com/ClickHouse/ClickHouse/pull/83271) ([Raúl Marín](https://github.com/Algunenano)).
- Fix possible crash in Variant type in UNION. [#83295](https://github.com/ClickHouse/ClickHouse/pull/83295) ([Pavel Kruglov](https://github.com/Avogar)).
- Fix LOGICAL\_ERROR in clickhouse-local for unsupported SYSTEM queries. [#83333](https://github.com/ClickHouse/ClickHouse/pull/83333) ([Surya Kant Ranjan](https://github.com/iit2009046)).
- Fix `no_sign_request` for S3 client. It can be used to explicitly avoid signing S3 requests. It can also be defined for specific endpoints using endpoint-based settings. [#83379](https://github.com/ClickHouse/ClickHouse/pull/83379) ([Antonio Andelic](https://github.com/antonio2368)).
- Fixes a crash that may happen for a query with a setting 'max\_threads=1' when executed under load with CPU scheduling enabled. [#83387](https://github.com/ClickHouse/ClickHouse/pull/83387) ([Fan Ziqi](https://github.com/f2quantum)).
- Fix `TOO_DEEP_SUBQUERIES` exception when CTE definition references another table expression with the same name. [#83413](https://github.com/ClickHouse/ClickHouse/pull/83413) ([Dmitry Novik](https://github.com/novikd)).
- Fix incorrect behavior when executing `REVOKE S3 ON system.*` revokes S3 permissions for `*.*`. This fixes [#83417](https://github.com/ClickHouse/ClickHouse/issues/83417). [#83420](https://github.com/ClickHouse/ClickHouse/pull/83420) ([pufit](https://github.com/pufit)).
- Do not share async\_read\_counters between queries. [#83423](https://github.com/ClickHouse/ClickHouse/pull/83423) ([Azat Khuzhin](https://github.com/azat)).
- Disable parallel replicas when a subquery contains the FINAL. [#83455](https://github.com/ClickHouse/ClickHouse/pull/83455) ([zoomxi](https://github.com/zoomxi)).
- Resolve minor integer overflow in configuration of setting `role_cache_expiration_time_seconds` (issue [#83374](https://github.com/ClickHouse/ClickHouse/issues/83374)). [#83461](https://github.com/ClickHouse/ClickHouse/pull/83461) ([wushap](https://github.com/wushap)).
- Fix a bug introduced in <https://github.com/ClickHouse/ClickHouse/pull/79963>. When inserting into an MV with a definer, the permission check should use the definer's grants. This fixes [#79951](https://github.com/ClickHouse/ClickHouse/issues/79951). [#83502](https://github.com/ClickHouse/ClickHouse/pull/83502) ([pufit](https://github.com/pufit)).
- Disable bounds-based file pruning for iceberg array element and iceberg map values, including all their nested subfields. [#83520](https://github.com/ClickHouse/ClickHouse/pull/83520) ([Daniil Ivanik](https://github.com/divanik)).
- Fix possible file cache not initialized errors when it's used as a temporary data storage. [#83539](https://github.com/ClickHouse/ClickHouse/pull/83539) ([Bharat Nallan](https://github.com/bharatnc)).
- Keeper fix: update total watch count correctly when ephemeral nodes are deleted on session close. [#83583](https://github.com/ClickHouse/ClickHouse/pull/83583) ([Antonio Andelic](https://github.com/antonio2368)).
- Fix incorrect memory around max\_untracked\_memory. [#83607](https://github.com/ClickHouse/ClickHouse/pull/83607) ([Azat Khuzhin](https://github.com/azat)).