1. Delete useless variables
2. Add const modifier for read-only function
3. Delete the empty destructor, the compiler will automatically generate it, refer to the 3/5/0 rule:
[https://en.cppreference.com/w/cpp/language/rule_of_three]
4. It is recommended to add the override keyword (instead of the virtual keyword) to the subclass virtual function.
Override will let the compiler help check and improve security. This is also the reason why C++11 introduces override
The previous DataSourceFunction inherited from RichSourceFunction.
As a result, no matter how much the parallelism of flink is set, the parallelism of DataSourceFunction is only 1.
Now modify it to RichParallelSourceFunction.
And when flink has multiple degrees of parallelism, assign the doris data to each parallelism.
For example, read dorisPartitions.size = 10, flink.parallelism = 4
The task is split as follows:
task0: dorisPartitions[0],[4],[8]
task1: dorisPartitions[1],[5],[9]
task2: dorisPartitions[2],[6]
task3: dorisPartitions[3],[7]
If the memory exceeds the limit when be generates a materialized view or schema change,
a more detailed log about limit and configuration will be prompted..
1. Fix some memory leaks
2. Remove redundant and invalid code
3. Fix some buggy writes to reduce extra memory copies and return null pointers to string
4. Reframing the naming to make the structure clearer
At present, there are defects in the chapter on debugging FE in doc. My colleagues and I stepped on the pit when
building the debugging environment, so I want to improve this chapter in combination with my own stepping on the pit
experience.
The following is my explanation of the changes:
1. mkdir -p ./thirdparty/installed/bin
explain: When I downloaded versions 0.14 and 0.15, there were no files under thirdparty, so I didn't know whether to
create it myself or what to do. Finally, I decided to create it myself. I think it's necessary to add instructions here.
2. Add installation thrift@0.13.0 Failed handling method.
explain: My colleagues and I failed to find the installation package when executing the installation command, and finally
found a solution on GitHub. Therefore, I added the handling method of the problem to avoid other Mac users from
getting stuck in this place.
3. Fixed an error in the generated code description.
explain: Before I finished building the code, I debugged FE, and I failed all the time. Idea hints that no files can be found.
Later, after consulting with morningman in wechat group, it was understood that `mvn install -DskipTests` does not
need to execute `mvn generate-sources` after execution. This is inconsistent with the description in the document and
needs to be corrected.
code refactor: improve code's readability, avoid const_cast
1. make loop simpler and clearer by using range-based loop grammar, it's safer than old loop style
2. iteration for _row_desc.tuple_descriptors() use index replace index and iterator mixed
3. add new function To cast_to(From from), use this union-based casting between two types to replace reinterpret_cast, this new cast is more readable
4. avoid using the same variable name for nested loop, it's dangerous
5. add const keyword for member functions followed CppCoreGuidelines
Close related #7334
1. Fix bug describe in [Bug] show frontends cause FE oom #7334
2. Fix error of CurrentConnected fields in show frontends result.
3. Add more FAQ
Fix the problem that when the source column of the lateral view comes from a inline view,
the column in the inline view cannot be materialized correctly.
At the same time, fix the problem that the correct output column cannot be projected
when the source column of the lateral view comes from a inline view.
It should be noted that when the column in the query is from a inline view column.
During semantic analysis and planning, it needs to be converted from tuple(virtual) to real tuple.
I found some small problems when I read code. So I add some small enhancement.
1. modify PR template. Now the template of PR isn't simple and clear. It's useful to refactor it.
2. some small change (typo, format .....)
issue: #7230
When getting the latest update time of a table, only compare the partitions of this query,
not all partitions of a table.
The goal is to improve the SqlCache hit rate.
When a broker load's task is failed, it may be retried by holding the
LoadJob's write lock and submit loading task to a thread pool.
But submitting a task to thread pool may be blocked for at most 60 seconds
(depends on BlockPolicy), so it will hold write lock for too long.
the tuple String Slot's ptr and len are not assigned appropriately on send side, the receive side may crash in some situation.
detail description:
on send side, when we call RowBatch::serialize(PRowBatch* output_batch) to pack RowBatch, the Tuple::deep_copy()
will be called, for each String Slot, only String Slots that is not null will set ptr and len with proper value, the null String
Slots will keep original status, the ptr member will point randomly and the len member may unexpect.
on recv side, unpack is processed by RowBatch::RowBatch(const RowDescriptor&, const PRowBatch&...), in this
function, each String Slot will transfer offset to valid string_val->ptr whether the String Slot is null or not.
but some business logic depends on string_val->len=0, such as AggregateFuncTraits::init(), HyperLogLog::deserialize()
will return correctly if slice.size<=0. so if string_val->len is set to 0 in send side, everything will be ok, otherwise server
may crash.
by netcomm viewpoint, we should make sure transfer correct data, it's sender's responsibility to set data with proper
value, and do not make any presume which way the recv side will use it.
Add `sink.batch.size` `sink.max-retries` options in `Doris Spark-connector`.
Be consistent with `link-connector` options .
eg:
```scala
df.write
.format("doris")
// specify maximum number of lines in a single flushing
.option("sink.batch.size",2048)
// specify number of retries after writing failed
.option("sink.max-retries",3)
.save()
```
In an HA environment, JE will retains as many reserved files.
the jdbje log become too large.
so we should limit the reserved files size, default set 1GB
Support lateral view of the result column in subquery.
For example:
```
select e1 from (select k2 as a from test_explode group by a) tmp1
lateral view explode_split(a, ",") tmp2 as e1;
```
The lateral view will parse the inline view column
and put the table function node above the subquery.
