title_wip

- While running the MODIFY COLUMN query for materialized views, check the inner table's structure to ensure every column exists. [#47427](https://github.com/ClickHouse/ClickHouse/pull/47427) ([sunny](https://github.com/sunny19930321)).
- Added table `system.keywords` which contains all the keywords from parser. Mostly needed and will be used for better fuzzing and syntax highlighting. [#51808](https://github.com/ClickHouse/ClickHouse/pull/51808) ([Nikita Mikhaylov](https://github.com/nikitamikhaylov)).
- Added support for parameterized view with analyzer to not analyze create parameterized view. Refactor existing parameterized view logic to not analyze create parameterized view. [#54211](https://github.com/ClickHouse/ClickHouse/pull/54211) ([SmitaRKulkarni](https://github.com/SmitaRKulkarni)).
- Ordinary database engine is deprecated. You will receive a warning in clickhouse-client if your server is using it. This closes [#52229](https://github.com/ClickHouse/ClickHouse/issues/52229). [#56942](https://github.com/ClickHouse/ClickHouse/pull/56942) ([shabroo](https://github.com/shabroo)).
- All zero copy locks related to a table have to be dropped when the table is dropped. The directory which contains these locks has to be removed also. [#57575](https://github.com/ClickHouse/ClickHouse/pull/57575) ([Sema Checherinda](https://github.com/CheSema)).
- Add short-circuit ability for `dictGetOrDefault` function. Closes [#52098](https://github.com/ClickHouse/ClickHouse/issues/52098). [#57767](https://github.com/ClickHouse/ClickHouse/pull/57767) ([jsc0218](https://github.com/jsc0218)).
- Allow declaring enum in external table structure. [#57857](https://github.com/ClickHouse/ClickHouse/pull/57857) ([Duc Canh Le](https://github.com/canhld94)).
- Running `ALTER COLUMN MATERIALIZE` on a column with `DEFAULT` or `MATERIALIZED` expression now writes the correct values: The default value for existing parts with default value or the non-default value for existing parts with non-default value. Previously, the default value was written for all existing parts. [#58023](https://github.com/ClickHouse/ClickHouse/pull/58023) ([Duc Canh Le](https://github.com/canhld94)).
- Enabled a backoff logic (e.g. exponential). Will provide an ability for reduced CPU usage, memory usage and log file sizes. [#58036](https://github.com/ClickHouse/ClickHouse/pull/58036) ([MikhailBurdukov](https://github.com/MikhailBurdukov)).
- Consider lightweight deleted rows when selecting parts to merge. [#58223](https://github.com/ClickHouse/ClickHouse/pull/58223) ([Zhuo Qiu](https://github.com/jewelzqiu)).
- Allow to define `volume_priority` in `storage_configuration`. [#58533](https://github.com/ClickHouse/ClickHouse/pull/58533) ([Andrey Zvonov](https://github.com/zvonand)).
- Add support for Date32 type in T64 codec. [#58738](https://github.com/ClickHouse/ClickHouse/pull/58738) ([Hongbin Ma](https://github.com/binmahone)).
- This PR makes http/https connections reusable for all uses cases. Even when response is 3xx or 4xx. [#58845](https://github.com/ClickHouse/ClickHouse/pull/58845) ([Sema Checherinda](https://github.com/CheSema)).
- Added comments for columns for more system tables. Continuation of <https://github.com/ClickHouse/ClickHouse/pull/58356>. [#59016](https://github.com/ClickHouse/ClickHouse/pull/59016) ([Nikita Mikhaylov](https://github.com/nikitamikhaylov)).
- Now we can use virtual columns in PREWHERE. It's worthwhile for non-const virtual columns like `_part_offset`. [#59033](https://github.com/ClickHouse/ClickHouse/pull/59033) ([Amos Bird](https://github.com/amosbird)).
- Settings for the Distributed table engine can now be specified in the server configuration file (similar to MergeTree settings), e.g. `<distributed> <flush_on_detach>false</flush_on_detach> </distributed>`. [#59291](https://github.com/ClickHouse/ClickHouse/pull/59291) ([Azat Khuzhin](https://github.com/azat)).
- Keeper improvement: cache only a certain amount of logs in-memory controlled by `latest_logs_cache_size_threshold` and `commit_logs_cache_size_threshold`. [#59460](https://github.com/ClickHouse/ClickHouse/pull/59460) ([Antonio Andelic](https://github.com/antonio2368)).
- Instead using a constant key, now object storage generates key for determining remove objects capability. [#59495](https://github.com/ClickHouse/ClickHouse/pull/59495) ([Sema Checherinda](https://github.com/CheSema)).
- Don't infer floats in exponential notation by default. Add a setting `input_format_try_infer_exponent_floats` that will restore previous behaviour (disabled by default). Closes [#59476](https://github.com/ClickHouse/ClickHouse/issues/59476). [#59500](https://github.com/ClickHouse/ClickHouse/pull/59500) ([Kruglov Pavel](https://github.com/Avogar)).
- Allow alter operations to be surrounded by parenthesis. The emission of parentheses can be controlled by the `format_alter_operations_with_parentheses` config. By default in formatted queries the parentheses are emitted as we store the formatted alter operations in some places as metadata (e.g.: mutations). The new syntax clarifies some of the queries where alter operations end in a list. E.g.: `ALTER TABLE x MODIFY TTL date GROUP BY a, b, DROP COLUMN c` cannot be parsed properly with the old syntax. In the new syntax the query `ALTER TABLE x (MODIFY TTL date GROUP BY a, b), (DROP COLUMN c)` is obvious. Older versions are not able to read the new syntax, therefore using the new syntax might cause issues if newer and older version of ClickHouse are mixed in a single cluster. [#59532](https://github.com/ClickHouse/ClickHouse/pull/59532) ([János Benjamin Antal](https://github.com/antaljanosbenjamin)).
- Bumped Intel QPL (used by codec `DEFLATE_QPL`) from v1.3.1 to v1.4.0 . Also fixed a bug for polling timeout mechanism, as we observed in same cases timeout won't work properly, if timeout happen, IAA and CPU may process buffer concurrently. So far, we'd better make sure IAA codec status is not QPL\_STS\_BEING\_PROCESSED, then fallback to SW codec. [#59551](https://github.com/ClickHouse/ClickHouse/pull/59551) ([jasperzhu](https://github.com/jinjunzh)).
- Add positional pread in libhdfs3. If you want to call positional read in libhdfs3, use the hdfsPread function in hdfs.h as follows. `tSize hdfsPread(hdfsFS fs, hdfsFile file, void * buffer, tSize length, tOffset position);`. [#59624](https://github.com/ClickHouse/ClickHouse/pull/59624) ([M1eyu](https://github.com/M1eyu2018)).
- Check for stack overflow in parsers even if the user misconfigured the `max_parser_depth` setting to a very high value. This closes [#59622](https://github.com/ClickHouse/ClickHouse/issues/59622). [#59697](https://github.com/ClickHouse/ClickHouse/pull/59697) ([Alexey Milovidov](https://github.com/alexey-milovidov)).
- Unify xml and sql created named collection behaviour in kafka storage. [#59710](https://github.com/ClickHouse/ClickHouse/pull/59710) ([Pervakov Grigorii](https://github.com/GrigoryPervakov)).
- Allow uuid in replica\_path if CREATE TABLE explicitly has it. [#59908](https://github.com/ClickHouse/ClickHouse/pull/59908) ([Azat Khuzhin](https://github.com/azat)).
- Add column `metadata_version` of ReplicatedMergeTree table in `system.tables` system table. [#59942](https://github.com/ClickHouse/ClickHouse/pull/59942) ([Maksim Kita](https://github.com/kitaisreal)).
- Keeper improvement: add retries on failures for Disk related operations. [#59980](https://github.com/ClickHouse/ClickHouse/pull/59980) ([Antonio Andelic](https://github.com/antonio2368)).
- Add new config setting `backups.remove_backup_files_after_failure`: `<clickhouse> <backups> <remove_backup_files_after_failure>true</remove_backup_files_after_failure> </backups> </clickhouse>`. [#60002](https://github.com/ClickHouse/ClickHouse/pull/60002) ([Vitaly Baranov](https://github.com/vitlibar)).
- Use multiple threads while reading the metadata of tables from a backup while executing the RESTORE command. [#60040](https://github.com/ClickHouse/ClickHouse/pull/60040) ([Vitaly Baranov](https://github.com/vitlibar)).