```
create table kafka
(
a UInt32,
a_str String Alias toString(a)
) engine = Kafka;
create table data
(
a UInt32;
a_str String
) engine = MergeTree
order by tuple();
create materialized view data_mv to data
(
a UInt32,
a_str String
) as
select a, a_str from kafka;
```
Alias type works as expected in comparison with MATERIALIZED/EPHEMERAL
or column with default expression.
Ref: https://github.com/ClickHouse/ClickHouse/pull/47138
Co-authored-by: Azat Khuzhin <a3at.mail@gmail.com>
ASan report:
==1==ERROR: AddressSanitizer: stack-use-after-scope on address 0x7f7540186b20 at pc 0x55656ef458ad bp 0x7f754114acf0 sp 0x7f754114a4b8
READ of size 2 at 0x7f7540186b20 thread T2 (TCPHandler)
0 0x55656ef458ac in __asan_memcpy (/usr/bin/clickhouse+0x11b028ac) (BuildId: 6ba63057df561f6dc16fb8fd7623fd858bf327d1)
1 0x55659f62daf8 in rd_kafka_msg_new00 build_docker/./contrib/librdkafka/src/rdkafka_msg.c:192:3
2 0x55659f62daf8 in rd_kafka_msg_new0 build_docker/./contrib/librdkafka/src/rdkafka_msg.c:257:8
3 0x55659f630635 in rd_kafka_producev build_docker/./contrib/librdkafka/src/rdkafka_msg.c:642:23
4 0x55659f4a865c in cppkafka::Producer::do_produce() build_docker/./contrib/cppkafka/src/producer.cpp:128:19
5 0x55659f4a8306 in cppkafka::Producer::produce() build_docker/./contrib/cppkafka/src/producer.cpp:69:5
6 0x5565961e748c in DB::KafkaProducer::produce() build_docker/./src/Storages/Kafka/KafkaProducer.cpp:70:23
7 0x5565962155b2 in DB::MessageQueueSink::consume(DB::Chunk) build_docker/./src/Storages/MessageQueueSink.cpp:64:23
8 0x5565980b9e8e in DB::SinkToStorage::onConsume(DB::Chunk) build_docker/./src/Processors/Sinks/SinkToStorage.cpp:18:5
Signed-off-by: Azat Khuzhin <a.khuzhin@semrush.com>
The Kafka table engine allows global configuration and per-Kafka-topic
configuration. The latter uses syntax <kafka_TOPIC>, e.g. for topic
"football":
<kafka_football>
<retry_backoff_ms>250</retry_backoff_ms>
<fetch_min_bytes>100000</fetch_min_bytes>
</kafka_football>
Some users had to find out the hard way that such configuration doesn't
take effect if the topic name contains a period, e.g. "sports.football".
The reason is that ClickHouse configuration framework already uses
periods as level separators to descend the configuration hierarchy.
(Besides that, per-topic configuration at the same level as global
configuration could be considered ugly.)
Note that Kafka topics may contain characters "a-zA-Z0-9._-" (*) and
a tree-like topic organization using periods is quite common in
practice.
This PR deprecates the existing per-topic configuration syntax (but
continues to support it for backward compat) and introduces a new
per-topic configuration syntax below the global Kafka configuration of
the form:
<kafka>
<topic name="football">
<retry_backoff_ms>250</retry_backoff_ms>
<fetch_min_bytes>100000</fetch_min_bytes>
</topic>
</kafka>
The period restriction doesn't apply to XML attributes, so <topic
name="sports.football"> will work. Also, everything Kafka-related is
below <kafka>.
Considered but rejected alternatives:
- Extending Poco ConfigurationView with custom separators (e.g."/"
instead of "."). Won't work easily because ConfigurationView only
builds a path but defers descending the configuration tree to the
normal configuration classes.
- Reloading the configuration file in StorageKafka (instead of reading
the loaded file) but with a custom separator. This mode is supported
by XML configuration. Too ugly and error-prone since the true
configuration is composed from multiple configuration files.
(*) https://stackoverflow.com/a/37067544
* save format string for NetException
* format exceptions
* format exceptions 2
* format exceptions 3
* format exceptions 4
* format exceptions 5
* format exceptions 6
* fix
* format exceptions 7
* format exceptions 8
* Update MergeTreeIndexGin.cpp
* Update AggregateFunctionMap.cpp
* Update AggregateFunctionMap.cpp
* fix
* Rename DDLDependencyVisitor -> DDLLoadingDependencyVisitor.
* Move building a loading graph to TablesLoader.
* Implement referential dependencies for tables and use them
when restoring tables from a backup.
* Remove StorageID::operator < (because of its inconsistency with ==).
* Add new tests.
* Fix test.
* Fix memory leak.
Co-authored-by: Nikita Mikhaylov <mikhaylovnikitka@gmail.com>
- lots of static_cast
- add safe_cast
- types adjustments
- config
- IStorage::read/watch
- ...
- some TODO's (to convert types in future)
P.S. That was quite a journey...
v2: fixes after rebase
v3: fix conflicts after #42308 merged
Signed-off-by: Azat Khuzhin <a.khuzhin@semrush.com>
This makes the target location consistent with other auto-generated
files like config_formats.h, config_core.h, and config_functions.h and
simplifies the build of clickhouse_common.
