Project: ClickHouse (App Definition and Development / Database)
File: v20.5.4.40-stable.md

Backported in : Fix " Index not used for IN operator with literals", performance regression introduced around v19.3. (). Backported in : Fix performance for selects with `UNION` caused by wrong limit for the total number of threads. Fixes . (). Backported in : Fixed the behaviour when `SummingMergeTree` engine sums up columns from partition key. Added an exception in case of explicit definition of columns to sum which intersects with partition key columns. This fixes . (). Backported in : Fixed the behaviour when during multiple sequential inserts in `StorageFile` header for some special types was written more than once. This fixed . (). Backported in : kafka: fix SIGSEGV if there is an message with error in the middle of the batch. (). Backported in : Fix TOTALS/ROLLUP/CUBE for aggregate functions with `-State` and `Nullable` arguments. This fixes . (). Backported in : Allow to CLEAR column even if there are depending DEFAULT expressions. This fixes . (). Backported in : Avoid exception when negative or floating point constant is used in WHERE condition for indexed tables. This fixes . (). Backported in : Fix crash in JOIN with dictionary when we are joining over expression of dictionary key: `t JOIN dict ON expr(dict.id) = t.id`. Disable dictionary join optimisation for this case. (). Backported in : Fixed performance issue, while reading from compact parts. (). Backported in : Fixing race condition in live view tables which could cause data duplication. (). Backported in : Now ClickHouse will recalculate checksums for parts when file `checksums.txt` is absent. Broken since . (). Backported in : Fix error `Output of TreeExecutor is not sorted` for `OPTIMIZE DEDUPLICATE`. Fixes . (). Backported in : Fix possible `Pipeline stuck` error for queries with external sorting. Fixes . (). Backported in : Better exception message in disk access storage. (). Backported in : Exception `There is no supertype...` can be thrown during `ALTER ... UPDATE` in unexpected cases (e.g. when subtracting from UInt64 column). This fixes . This fixes . (). Backported in : Add support for function `if` with `Array(UUID)` arguments. This fixes . (). Backported in : Fix SIGSEGV in StorageKafka when broker is unavailable (and not only). (). Backported in : fixes fix bloom filter index with const expression. (). Backported in : fixes allow push predicate when subquery contains with clause. (). Backported in : Fix memory tracking for inputformatparallel_parsing (by attaching thread to group). (). Backported in : Fix performance with large tuples, which are interpreted as functions in `IN` section. The case when user write `WHERE x IN tuple(1, 2, ...)` instead of `WHERE x IN (1, 2, ...)` for some obscure reason. (). Backported in : Corrected mergewithttl_timeout logic which did not work well when expiration affected more than one partition over one time interval. (Authored by @excitoon). (). Backported in : Fix `Block structure mismatch` error for queries with `UNION` and `JOIN`. Fixes . (). Backported in : Fix crash which was possible for queries with `ORDER BY` tuple and small `LIMIT`. Fixes . (). Backported in : Fix wrong index analysis with functions. It could lead to pruning wrong parts, while reading from `MergeTree` tables. Fixes . Fixes . ().