ClickHouse/docs/changelogs/v21.9.5.16-stable.md

ClickHouse release v21.9.5.16-stable FIXME as compared to v21.9.4.35-stable

Improvement

• Backported in #29897: Added partitioned table prefix 'p' for the query for fetching replica identity index. #29828 (Shoh Jahon).
• Backported in #29943: Update zoneinfo files to 2021c. #29925 (Alexey Milovidov).

Bug Fix

• Backported in #29775: Allow using a materialized column as the sharding key in a distributed table even if insert_allow_materialized_columns=0:. #28637 (Vitaly Baranov).
• Backported in #29126: Fix bug in clickhouse-keeper-converter which can lead to incorrect ZooKeeper log deserialization. #29071 (小路).
• Backported in #29972: Fix shutdown of AccessControlManager. Now there can't be reloading of the configuration after AccessControlManager has been destroyed. This PR fixes the flaky test test_user_directories/test.py::test_relative_path. #29951 (Vitaly Baranov).
• Backported in #30052: Fix releasing query ID and session ID at the end of query processing while handing gRPC call. This PR fixes flaky test test_grpc_protocol/test.py::test_session. #29954 (Vitaly Baranov).

Bug Fix (user-visible misbehaviour in official stable or prestable release)

• Backported in #29055: Fix invalid constant type conversion when nullable or lowcardinality primary key is used. #28636 (Amos Bird).
• Backported in #29107: Fix waiting for mutation with mutations_sync=2. #28889 (Azat Khuzhin).
• Backported in #29815: Do not allow to reuse previous credentials in case of inter-server secret (Before INSERT via Buffer/Kafka to Distributed table with interserver secret configured for that cluster, may re-use previously set user for that connection). #29060 (Azat Khuzhin).
• Backported in #29399: Send normal Database doesn't exist error (UNKNOWN_DATABASE) to the client (via TCP) instead of Attempt to read after eof (ATTEMPT_TO_READ_AFTER_EOF). #29229 (Azat Khuzhin).
• Backported in #29356: Fix possible Table columns structure in ZooKeeper is different from local table structure exception while recreating or creating new replicas of ReplicatedMergeTree, when one of table columns have default expressions with case-insensitive functions. #29266 (Anton Popov).
• Backported in #29451: Fix failed assertion in ReadBufferFromHDFS. Update libhdfs3 library to be able to run in tests in debug. Closes #29251. Closes #27814. #29276 (Kseniia Sumarokova).
• Backported in #29301: Fix connection timeouts (send_timeout/receive_timeout). #29282 (Azat Khuzhin).
• Backported in #29383: Remove window function nth_value as it is not memory-safe. This closes #29347. #29348 (Alexey Milovidov).
• Backported in #29438: Fix replicated access storage not shutting down cleanly when misconfigured. #29388 (Kevin Michel).
• Backported in #29489: Fix Logical error Cannot capture columns in functions greatest/least. Closes #29334. #29454 (Kruglov Pavel).
• Backported in #29536: Fix possible Block structure mismatch for subqueries with pushed-down HAVING predicate. Fixes #29010. #29475 (Nikolai Kochetov).
• Backported in #29592: In ODBC bridge add retries for error Invalid cursor state. It is a retriable error. Closes #29473. #29518 (Kseniia Sumarokova).
• Backported in #29572: Fix bug in check pathStartsWith becuase there was bug with the usage of std::mismatch: The behavior is undefined if the second range is shorter than the first range.. #29531 (Kseniia Sumarokova).
• Backported in #29630: Fix rare segfault in ALTER MODIFY query when using incorrect table identifier in DEFAULT expression like x.y.z... Fixes #29184. #29573 (alesapin).
• Backported in #29658: Fix JIT expression compilation with aliases and short-circuit expression evaluation. Closes #29403. #29574 (Maksim Kita).
• Backported in #29751: Condition in filter predicate could be lost after push-down optimisation. #29625 (Nikolai Kochetov).
• Backported in #29849: Fix concurrent access to LowCardinality during GROUP BY (leads to SIGSEGV). #29782 (Azat Khuzhin).
• Backported in #29909: Fix bad cast in ATTACH TABLE ... FROM 'path' query when non-string literal is used instead of path. It may lead to reading of uninitialized memory. #29790 (Alexey Milovidov).
• Backported in #29865: Avoid Timeout exceeded: elapsed 18446744073.709553 seconds error that might happen in extremely rare cases, presumably due to some bug in kernel. Fixes #29154. #29811 (Alexander Tokmakov).
• Backported in #30024: MaterializedMySQL: Fix an issue where if the connection to MySQL was lost, only parts of a transaction could be processed. #29837 (Håvard Kvålen).
• Backported in #29878: Fix system tables recreation check (fails to detect changes in enum values). #29857 (Azat Khuzhin).
• Backported in #30057: Fix potential resource leak of the concurrent query limit of merge tree tables introduced in https://github.com/ClickHouse/ClickHouse/pull/19544 . #29879 (Amos Bird).
• Backported in #30204: Fix data-race between LogSink::writeMarks() and LogSource in StorageLog. #29946 (Azat Khuzhin).
• Backported in #30209: Fix possible data-race between FileChecker and StorageLog/StorageStripeLog. #29959 (Azat Khuzhin).
• Backported in #30070: Fix crash of sample by tuple(), closes #30004. #30016 (flynn).
• Backported in #30128: Dropped Memory database might reappear after server restart, it's fixed (#29795). Also added force_remove_data_recursively_on_drop setting as a workaround for Directory not empty error when dropping Ordinary database (because it's not possible to remove data leftovers manually in cloud environment). #30054 (Alexander Tokmakov).
• Backported in #30262: FlatDictionary, HashedDictionary fix bytes_allocated calculation for nullable attributes. #30238 (Maksim Kita).
• Backported in #30306: Fix crash with shortcircuit and lowcardinality in multiIf. #30243 (Raúl Marín).
• Backported in #30290: Fix ComplexKeyHashedDictionary, ComplexKeySparseHashedDictionary parsing preallocate option from layout config. #30246 (Maksim Kita).

NO CL CATEGORY

• Avoid deadlocks when reading and writting on JOIN Engine tables at the same time. #30185 (Raúl Marín).