### ClickHouse release v23.8.9.54-lts (192a1d231fa) FIXME as compared to v23.8.8.20-lts (5e012a03bf2)
#### Improvement
* Backported in [#57668](https://github.com/ClickHouse/ClickHouse/issues/57668): Output valid JSON/XML on excetpion during HTTP query execution. Add setting `http_write_exception_in_output_format` to enable/disable this behaviour (enabled by default). [#52853](https://github.com/ClickHouse/ClickHouse/pull/52853) ([Kruglov Pavel](https://github.com/Avogar)).
* Backported in [#58491](https://github.com/ClickHouse/ClickHouse/issues/58491): Fix transfer query to MySQL compatible query. Fixes [#57253](https://github.com/ClickHouse/ClickHouse/issues/57253). Fixes [#52654](https://github.com/ClickHouse/ClickHouse/issues/52654). Fixes [#56729](https://github.com/ClickHouse/ClickHouse/issues/56729). [#56456](https://github.com/ClickHouse/ClickHouse/pull/56456) ([flynn](https://github.com/ucasfl)).
* Backported in [#57238](https://github.com/ClickHouse/ClickHouse/issues/57238): Fetching a part waits when that part is fully committed on remote replica. It is better not send part in PreActive state. In case of zero copy this is mandatory restriction. [#56808](https://github.com/ClickHouse/ClickHouse/pull/56808) ([Sema Checherinda](https://github.com/CheSema)).
* Backported in [#57655](https://github.com/ClickHouse/ClickHouse/issues/57655): Handle sigabrt case when getting PostgreSQl table structure with empty array. [#57618](https://github.com/ClickHouse/ClickHouse/pull/57618) ([Mikhail Kot](https://github.com/myrrc)).
* Backported in [#57582](https://github.com/ClickHouse/ClickHouse/issues/57582): Fix issue caught in https://github.com/docker-library/official-images/pull/15846. [#57571](https://github.com/ClickHouse/ClickHouse/pull/57571) ([Mikhail f. Shiryaev](https://github.com/Felixoid)).
#### Bug Fix (user-visible misbehavior in an official stable release)
* Backported in [#58324](https://github.com/ClickHouse/ClickHouse/issues/58324): Flatten only true Nested type if flatten_nested=1, not all Array(Tuple). [#56132](https://github.com/ClickHouse/ClickHouse/pull/56132) ([Kruglov Pavel](https://github.com/Avogar)).
* Backported in [#57395](https://github.com/ClickHouse/ClickHouse/issues/57395): Fix ALTER COLUMN with ALIAS that previously threw the `NO_SUCH_COLUMN_IN_TABLE` exception. Closes [#50927](https://github.com/ClickHouse/ClickHouse/issues/50927). [#56493](https://github.com/ClickHouse/ClickHouse/pull/56493) ([Nikolay Degterinsky](https://github.com/evillique)).
* Backported in [#57449](https://github.com/ClickHouse/ClickHouse/issues/57449): Now ALTER columns which are incompatible with columns used in some projections will be forbidden. Previously it could result in incorrect data. This fixes [#56932](https://github.com/ClickHouse/ClickHouse/issues/56932). This PR also allows RENAME of index columns, and improves the exception message by providing clear information on the affected indices or projections causing the prevention. [#56948](https://github.com/ClickHouse/ClickHouse/pull/56948) ([Amos Bird](https://github.com/amosbird)).
* Backported in [#57281](https://github.com/ClickHouse/ClickHouse/issues/57281): Fix segfault after ALTER UPDATE with Nullable MATERIALIZED column. Closes [#42918](https://github.com/ClickHouse/ClickHouse/issues/42918). [#57147](https://github.com/ClickHouse/ClickHouse/pull/57147) ([Nikolay Degterinsky](https://github.com/evillique)).
* Backported in [#57247](https://github.com/ClickHouse/ClickHouse/issues/57247): Fix incorrect JOIN plan optimization with partially materialized normal projection. This fixes [#57194](https://github.com/ClickHouse/ClickHouse/issues/57194). [#57196](https://github.com/ClickHouse/ClickHouse/pull/57196) ([Amos Bird](https://github.com/amosbird)).
* Backported in [#57346](https://github.com/ClickHouse/ClickHouse/issues/57346): Fix `ReadonlyReplica` metric for some cases (e.g. when a table cannot be initialized because of difference in local and Keeper data). [#57267](https://github.com/ClickHouse/ClickHouse/pull/57267) ([Antonio Andelic](https://github.com/antonio2368)).
* Backported in [#58434](https://github.com/ClickHouse/ClickHouse/issues/58434): Fix working with read buffers in StreamingFormatExecutor, previously it could lead to segfaults in Kafka and other streaming engines. [#57438](https://github.com/ClickHouse/ClickHouse/pull/57438) ([Kruglov Pavel](https://github.com/Avogar)).
* Backported in [#57539](https://github.com/ClickHouse/ClickHouse/issues/57539): Fix parsing of `SYSTEM STOP LISTEN TCP SECURE`. [#57483](https://github.com/ClickHouse/ClickHouse/pull/57483) ([joelynch](https://github.com/joelynch)).
* Backported in [#57779](https://github.com/ClickHouse/ClickHouse/issues/57779): Conf ``` <user_directories><replicated><zookeeper_path>/clickhouse/access/</zookeeper_path></replicated></user_directories> ``` sql ``` show settings like 'ignore_on_cluster_for_replicated_access_entities_queries' ┌─name─────────────────────────────────────────────────────┬─type─┬─value─┐ │ ignore_on_cluster_for_replicated_access_entities_queries │ bool │ 1 │ └──────────────────────────────────────────────────────────┴──────┴───────┘. [#57538](https://github.com/ClickHouse/ClickHouse/pull/57538) ([MikhailBurdukov](https://github.com/MikhailBurdukov)).
* Backported in [#58256](https://github.com/ClickHouse/ClickHouse/issues/58256): Disable system.kafka_consumers by default (due to possible live memory leak). [#57822](https://github.com/ClickHouse/ClickHouse/pull/57822) ([Azat Khuzhin](https://github.com/azat)).
* Backported in [#57923](https://github.com/ClickHouse/ClickHouse/issues/57923): Fix invalid memory access in BLAKE3. [#57876](https://github.com/ClickHouse/ClickHouse/pull/57876) ([Raúl Marín](https://github.com/Algunenano)).
* Backported in [#58084](https://github.com/ClickHouse/ClickHouse/issues/58084): Normilize function names in `CREATE INDEX` query. Avoid `Existing table metadata in ZooKeeper differs in skip indexes` errors if an alias was used insead of canonical function name when creating an index. [#57906](https://github.com/ClickHouse/ClickHouse/pull/57906) ([Alexander Tokmakov](https://github.com/tavplubix)).
* Backported in [#58110](https://github.com/ClickHouse/ClickHouse/issues/58110): Keeper fix: Leader should correctly fail on preprocessing a request if it is not initialized. [#58069](https://github.com/ClickHouse/ClickHouse/pull/58069) ([Antonio Andelic](https://github.com/antonio2368)).
* Backported in [#58155](https://github.com/ClickHouse/ClickHouse/issues/58155): Fix Integer overflow in Poco::UTF32Encoding. [#58073](https://github.com/ClickHouse/ClickHouse/pull/58073) ([Andrey Fedotov](https://github.com/anfedotoff)).
* Backported in [#58188](https://github.com/ClickHouse/ClickHouse/issues/58188): Parallel parsing for `JSONCompactEachRow` could work incorrectly in previous versions. This closes [#58180](https://github.com/ClickHouse/ClickHouse/issues/58180). [#58181](https://github.com/ClickHouse/ClickHouse/pull/58181) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
* Backported in [#58301](https://github.com/ClickHouse/ClickHouse/issues/58301): Fix parallel parsing for JSONCompactEachRow. [#58250](https://github.com/ClickHouse/ClickHouse/pull/58250) ([Kruglov Pavel](https://github.com/Avogar)).
* NO CL ENTRY: 'Update PeekableWriteBuffer.cpp'. [#57701](https://github.com/ClickHouse/ClickHouse/pull/57701) ([Kruglov Pavel](https://github.com/Avogar)).
#### NOT FOR CHANGELOG / INSIGNIFICANT
* Pin alpine version of integration tests helper container [#57669](https://github.com/ClickHouse/ClickHouse/pull/57669) ([Mikhail f. Shiryaev](https://github.com/Felixoid)).
* Remove heavy rust stable toolchain [#57905](https://github.com/ClickHouse/ClickHouse/pull/57905) ([Mikhail f. Shiryaev](https://github.com/Felixoid)).
