ClickHouse/docs/changelogs/v21.5.7.9-stable.md

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1	2022

2022 Changelog

ClickHouse release v21.5.7.9-stable FIXME as compared to v21.5.6.6-stable

Improvement

• Backported in #24581: Disable min_bytes_to_use_mmap_io by default. #23322 (Azat Khuzhin).
• Backported in #25222: Here will be listed all the bugs that I am gonna to fix in this PR. #23518 (Nikita Mikhaylov).
• Backported in #24793: Avoid hiding errors like Limit for rows or bytes to read exceeded for scalar subqueries. #24545 (nvartolomei).

Bug Fix

• Backported in #24928: Fix implementation of connection pool of PostgreSQL engine. Closes #23897. #23909 (Kseniia Sumarokova).
• Backported in #24568: Use old modulo function version when used in partition key. Closes #23508. #24157 (Kseniia Sumarokova).
• Backported in #24726: In "multipart/form-data" message consider the CRLF preceding a boundary as part of it. Fixes #23905. #24399 (Ivan).
• Backported in #24824: - Fixed the deadlock that can happen during LDAP role (re)mapping, when LDAP group is mapped to a nonexistent local role. #24431 (Denis Glazachev).
• Backported in #24772: Fix bug which can lead to ZooKeeper client hung inside clickhouse-server. #24721 (alesapin).
• Backported in #24935: - If ZooKeeper connection was lost and replica was cloned after restoring the connection, its replication queue might contain outdated entries. It's fixed. - Fixed crash when replication queue contains intersecting virtual parts. It may rarely happen if some data part was lost. Print error in log instead of terminating. #24777 (Alexander Tokmakov).
• Backported in #24854: Fix bug when exception Mutation was killed can be thrown to the client on mutation wait when mutation not loaded into memory yet. #24809 (alesapin).
• Backported in #24986: Allow NULL values in postgresql protocol. Closes #22622. #24857 (Kseniia Sumarokova).
• Backported in #25481: Fix "Missing columns" exception when joining Distributed Materialized View. #24870 (Azat Khuzhin).
• Backported in #24915: Fix extremely rare bug on low-memory servers which can lead to the inability to perform merges without restart. Possibly fixes #24603. #24872 (alesapin).
• Backported in #25183: Fixed bug with declaring S3 disk at root of bucket. Earlier, it reported an error: ``` [heather] 2021.05.10 02:11:11.932234 [ 72790 ] {2ff80b7b-ec53-41cb-ac35-19bb390e1759} executeQuery: Code: 36, e.displayText() = DB::Exception: Key name is empty in path style S3 URI: (http://172.17.0.2/bucket/) (version 21.6.1.1) (from 127.0.0.1:47994) (in query: SELECT policy_name FROM system.storage_policies), Stack trace (when copying this message, always include the lines below):. #24898 (Vladimir Chebotarev).
• Backported in #24950: Fix possible heap-buffer-overflow in Arrow. #24922 (Kruglov Pavel).
• Backported in #25024: Fix limit/offset settings for distributed queries (ignore on the remote nodes). #24940 (Azat Khuzhin).
• Backported in #25048: Fix extremely rare error Tagging already tagged part in replication queue during concurrent alter move/replace partition. Possibly fixes #22142. #24961 (alesapin).
• Backported in #25365: Fix serialization of splitted nested messages in Protobuf format. This PR fixes #24647. #25000 (Vitaly Baranov).
• Backported in #25101: Distinguish KILL MUTATION for different tables (fixes unexpected Cancelled mutating parts error). #25025 (Azat Khuzhin).
• Backported in #25558: Fix bug which allows creating tables with columns referencing themselves like a UInt32 ALIAS a + 1 or b UInt32 MATERIALIZED b. Fixes #24910, #24292. #25059 (alesapin).
• Backported in #25104: Fix bug with constant maps in mapContains that lead to error empty column was returned by function mapContains. Closes #25077. #25080 (Kruglov Pavel).
• Backported in #25141: Fix crash in query with cross join and joined_subquery_requires_alias = 0. Fixes #24011. #25082 (Nikolai Kochetov).
• Backported in #25214: Fixed an error which occurred while inserting a subset of columns using CSVWithNames format. Fixes #25129. #25169 (Nikita Mikhaylov).
• Backported in #25353: Fix TOCTOU error in installation script. #25277 (Alexey Milovidov).
• Backported in #25471: Fix joinGetOrNull with not-nullable columns. This fixes #24261. #25288 (Amos Bird).
• Backported in #25357: Fix Logical Error Cannot sum Array/Tuple in min/maxMap. #25298 (Kruglov Pavel).
• Backported in #25438: Support SimpleAggregateFunction(LowCardinality) for SummingMergeTree. Fixes #25134. #25300 (Nikolai Kochetov).
• Backported in #25362: On ZooKeeper connection loss ReplicatedMergeTree table might wait for background operations to complete before trying to reconnect. It's fixed, now background operations are stopped forcefully. #25306 (Alexander Tokmakov).
• Backported in #25386: Fix the possibility of non-deterministic behaviour of the quantileDeterministic function and similar. This closes #20480. #25313 (Alexey Milovidov).
• Backported in #25456: Fix lost WHERE condition in expression-push-down optimization of query plan (setting query_plan_filter_push_down = 1 by default). Fixes #25368. #25370 (Nikolai Kochetov).
• Backported in #25408: Fix REPLACE column transformer when used in DDL by correctly quoting the formated query. This fixes #23925. #25391 (Amos Bird).
• Backported in #25504: Fix segfault when sharding_key is absent in task config for copier. #25419 (Nikita Mikhaylov).

NO CL ENTRY

• NO CL ENTRY: 'Revert "Backport #24721 to 21.5: Remove endless wait from ZooKeeper client"'. #24798 (alesapin).

NOT FOR CHANGELOG / INSIGNIFICANT

• Try fix test_consistent_parts_after_clone_replica #24968 (Alexander Tokmakov).
• DictionaryLoader unnecessary dictionary configuration creation fix #25001 (Maksim Kita).
• odbc fix #25045 (Kseniia Sumarokova).