2019 Changelog

- Server exception got while sending insertion data is now being processed in client as well. [#5891](https://github.com/ClickHouse/ClickHouse/issues/5891) [#6711](https://github.com/ClickHouse/ClickHouse/pull/6711) ([dimarub2000](https://github.com/dimarub2000))
- Added a metric `DistributedFilesToInsert` that shows the total number of files in filesystem that are selected to send to remote servers by Distributed tables. The number is summed across all shards. [#6600](https://github.com/ClickHouse/ClickHouse/pull/6600) ([alexey-milovidov](https://github.com/alexey-milovidov))
- Move most of JOINs prepare logic from `ExpressionAction/ExpressionAnalyzer` to `AnalyzedJoin`. [#6785](https://github.com/ClickHouse/ClickHouse/pull/6785) ([Artem Zuikov](https://github.com/4ertus2))
- Fix TSan [warning](https://clickhouse-test-reports.s3.yandex.net/6399/c1c1d1daa98e199e620766f1bd06a5921050a00d/functional_stateful_tests_(thread).html) 'lock-order-inversion'. [#6740](https://github.com/ClickHouse/ClickHouse/pull/6740) ([Vasily Nemkov](https://github.com/Enmk))
- Better information messages about lack of Linux capabilities. Logging fatal errors with "fatal" level, that will make it easier to find in `system.text_log`. [#6441](https://github.com/ClickHouse/ClickHouse/pull/6441) ([alexey-milovidov](https://github.com/alexey-milovidov))
- When enable dumping temporary data to the disk to restrict memory usage during `GROUP BY`, `ORDER BY`, it didn't check the free disk space. The fix add a new setting `min_free_disk_space`, when the free disk space it smaller then the threshold, the query will stop and throw `ErrorCodes::NOT_ENOUGH_SPACE`. [#6678](https://github.com/ClickHouse/ClickHouse/pull/6678) ([Weiqing Xu](https://github.com/weiqxu)) [#6691](https://github.com/ClickHouse/ClickHouse/pull/6691) ([alexey-milovidov](https://github.com/alexey-milovidov))
- Removed recursive rwlock by thread. It makes no sense, because threads are reused between queries. `SELECT` query may acquire a lock in one thread, hold a lock from another thread and exit from first thread. In the same time, first thread can be reused by `DROP` query. This will lead to false "Attempt to acquire exclusive lock recursively" messages. [#6771](https://github.com/ClickHouse/ClickHouse/pull/6771) ([alexey-milovidov](https://github.com/alexey-milovidov))
- Split `ExpressionAnalyzer.appendJoin()`. Prepare a place in `ExpressionAnalyzer` for `MergeJoin`. [#6524](https://github.com/ClickHouse/ClickHouse/pull/6524) ([Artem Zuikov](https://github.com/4ertus2))
- Added `mysql_native_password` authentication plugin to MySQL compatibility server. [#6194](https://github.com/ClickHouse/ClickHouse/pull/6194) ([Yuriy Baranov](https://github.com/yurriy))
- Less number of `clock_gettime` calls; fixed ABI compatibility between debug/release in `Allocator` (insignificant issue). [#6197](https://github.com/ClickHouse/ClickHouse/pull/6197) ([alexey-milovidov](https://github.com/alexey-milovidov))
- Move `collectUsedColumns` from `ExpressionAnalyzer` to `SyntaxAnalyzer`. `SyntaxAnalyzer` makes `required_source_columns` itself now. [#6416](https://github.com/ClickHouse/ClickHouse/pull/6416) ([Artem Zuikov](https://github.com/4ertus2))
- Add setting `joined_subquery_requires_alias` to require aliases for subselects and table functions in `FROM` that more than one table is present (i.e. queries with JOINs). [#6733](https://github.com/ClickHouse/ClickHouse/pull/6733) ([Artem Zuikov](https://github.com/4ertus2))
- Extract `GetAggregatesVisitor` class from `ExpressionAnalyzer`. [#6458](https://github.com/ClickHouse/ClickHouse/pull/6458) ([Artem Zuikov](https://github.com/4ertus2))
- `system.query_log`: change data type of `type` column to `Enum`. [#6265](https://github.com/ClickHouse/ClickHouse/pull/6265) ([Nikita Mikhaylov](https://github.com/nikitamikhaylov))
- Static linking of `sha256_password` authentication plugin. [#6512](https://github.com/ClickHouse/ClickHouse/pull/6512) ([Yuriy Baranov](https://github.com/yurriy))
- Avoid extra dependency for the setting `compile` to work. In previous versions, the user may get error like `cannot open crti.o`, `unable to find library -lc` etc. [#6309](https://github.com/ClickHouse/ClickHouse/pull/6309) ([alexey-milovidov](https://github.com/alexey-milovidov))
- More validation of the input that may come from malicious replica. [#6303](https://github.com/ClickHouse/ClickHouse/pull/6303) ([alexey-milovidov](https://github.com/alexey-milovidov))
- Now `clickhouse-obfuscator` file is available in `clickhouse-client` package. In previous versions it was available as `clickhouse obfuscator` (with whitespace). [#5816](https://github.com/ClickHouse/ClickHouse/issues/5816) [#6609](https://github.com/ClickHouse/ClickHouse/pull/6609) ([dimarub2000](https://github.com/dimarub2000))
- Fixed deadlock when we have at least two queries that read at least two tables in different order and another query that performs DDL operation on one of tables. Fixed another very rare deadlock. [#6764](https://github.com/ClickHouse/ClickHouse/pull/6764) ([alexey-milovidov](https://github.com/alexey-milovidov))
- Added `os_thread_ids` column to `system.processes` and `system.query_log` for better debugging possibilities. [#6763](https://github.com/ClickHouse/ClickHouse/pull/6763) ([alexey-milovidov](https://github.com/alexey-milovidov))
- A workaround for PHP mysqlnd extension bugs which occur when `sha256_password` is used as a default authentication plugin (described in [#6031](https://github.com/ClickHouse/ClickHouse/issues/6031)). [#6113](https://github.com/ClickHouse/ClickHouse/pull/6113) ([Yuriy Baranov](https://github.com/yurriy))
- Remove unneeded place with changed nullability columns. [#6693](https://github.com/ClickHouse/ClickHouse/pull/6693) ([Artem Zuikov](https://github.com/4ertus2))
- Set default value of `queue_max_wait_ms` to zero, because current value (five seconds) makes no sense. There are rare circumstances when this settings has any use. Added settings `replace_running_query_max_wait_ms`, `kafka_max_wait_ms` and `connection_pool_max_wait_ms` for disambiguation. [#6692](https://github.com/ClickHouse/ClickHouse/pull/6692) ([alexey-milovidov](https://github.com/alexey-milovidov))
- Extract `SelectQueryExpressionAnalyzer` from `ExpressionAnalyzer`. Keep the last one for non-select queries. [#6499](https://github.com/ClickHouse/ClickHouse/pull/6499) ([Artem Zuikov](https://github.com/4ertus2))
- Removed duplicating input and output formats. [#6239](https://github.com/ClickHouse/ClickHouse/pull/6239) ([Nikolai Kochetov](https://github.com/KochetovNicolai))
- Allow user to override `poll_interval` and `idle_connection_timeout` settings on connection. [#6230](https://github.com/ClickHouse/ClickHouse/pull/6230) ([alexey-milovidov](https://github.com/alexey-milovidov))
- `MergeTree` now has an additional option `ttl_only_drop_parts` (disabled by default) to avoid partial pruning of parts, so that they dropped completely when all the rows in a part are expired. [#6191](https://github.com/ClickHouse/ClickHouse/pull/6191) ([Sergi Vladykin](https://github.com/svladykin))
- Type checks for set index functions. Throw exception if function got a wrong type. This fixes fuzz test with UBSan. [#6511](https://github.com/ClickHouse/ClickHouse/pull/6511) ([Nikita Vasilev](https://github.com/nikvas0))