techdocsmith commented on a change in pull request #11506:
URL: https://github.com/apache/druid/pull/11506#discussion_r680269609
##########
File path: docs/ingestion/native-batch.md
##########
@@ -366,8 +366,15 @@ Druid currently supports only one partition function.
#### Single-dimension range partitioning
> Single dimension range partitioning is currently not supported in the
> sequential mode of the Parallel task.
+
The Parallel task will use one subtask when you set `maxNumConcurrentSubTasks`
to 1.
+> Be aware that, with this technique, segment sizes could be skewed if your
chosen `partitionDimension` is also skewed in source data.
Review comment:
```suggestion
If you use this technique to partition your data, you can wind up with
varying segment sizes if the values for `partitionDimension` from your original
data are unequally distributed.
```
@petermarshallio , is there a recommended action in this case? Select
another dimension? Can autocompaction help?
##########
File path: docs/ingestion/native-batch.md
##########
@@ -366,8 +366,15 @@ Druid currently supports only one partition function.
#### Single-dimension range partitioning
> Single dimension range partitioning is currently not supported in the
> sequential mode of the Parallel task.
+
The Parallel task will use one subtask when you set `maxNumConcurrentSubTasks`
to 1.
+> Be aware that, with this technique, segment sizes could be skewed if your
chosen `partitionDimension` is also skewed in source data.
+
+> While it is technically possible to concatenate multiple dimensions into a
single new dimension
Review comment:
```suggestion
```
##########
File path: docs/ingestion/native-batch.md
##########
@@ -366,8 +366,15 @@ Druid currently supports only one partition function.
#### Single-dimension range partitioning
> Single dimension range partitioning is currently not supported in the
> sequential mode of the Parallel task.
+
The Parallel task will use one subtask when you set `maxNumConcurrentSubTasks`
to 1.
+> Be aware that, with this technique, segment sizes could be skewed if your
chosen `partitionDimension` is also skewed in source data.
+
+> While it is technically possible to concatenate multiple dimensions into a
single new dimension
+> that you go on to specify in `partitionDimension`, remember that you _must_
then use this newly concatenated dimension at query time
+> in order for segment pruning to be effective.
Review comment:
```suggestion
> It is possible to concatenate multiple dimensions into a single new
dimension to use for the `partitionDimension`. To take advantage of the
performance improvements of segment pruning in this case, you must use the
newly concatenated dimension at query time.
```
##########
File path: docs/ingestion/native-batch.md
##########
@@ -366,8 +366,15 @@ Druid currently supports only one partition function.
#### Single-dimension range partitioning
> Single dimension range partitioning is currently not supported in the
> sequential mode of the Parallel task.
+
The Parallel task will use one subtask when you set `maxNumConcurrentSubTasks`
to 1.
+> Be aware that, with this technique, segment sizes could be skewed if your
chosen `partitionDimension` is also skewed in source data.
+
+> While it is technically possible to concatenate multiple dimensions into a
single new dimension
+> that you go on to specify in `partitionDimension`, remember that you _must_
then use this newly concatenated dimension at query time
Review comment:
```suggestion
```
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