Implement streaming versions of Dataframe.collect methods #789
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Co-authored-by: Andrew Lamb <[email protected]>
alamb
reviewed
Jul 28, 2021
datafusion/src/dataframe.rs
Outdated
| /// # Ok(()) | ||
| /// # } | ||
| /// ``` | ||
| async fn collect_stream(&self) -> Result<SendableRecordBatchStream>; |
There was a problem hiding this comment.
What if we called this something like execute rather than collect_stream?
async fn execute_stream(&self) -> Result<SendableRecordBatchStream>;
This would mirror the naming of ExecutionPlan::execute and might make it clearer that collect means collect into a Vec and execute means get a stream
There was a problem hiding this comment.
Good idea. I renamed these to execute_stream and execute_stream_partitioned
|
|
||
| /// Convert the logical plan represented by this DataFrame into a physical plan and | ||
| /// execute it, collecting all resulting batches into memory while maintaining | ||
| /// partitioning | ||
| async fn collect_partitioned(&self) -> Result<Vec<Vec<RecordBatch>>> { | ||
| let state = self.ctx_state.lock().unwrap().clone(); |
There was a problem hiding this comment.
You could probably rewrite collect_partitioned to be in terms of collect_stream_partitioned:
collect(self.collect_stream_partitioned().await?)or something like that
There was a problem hiding this comment.
I've cleaned the code up and removed a fair bit of duplication now.
andygrove
changed the title
alamb
approved these changes
Jul 28, 2021
andygrove
pushed a commit
to andygrove/datafusion
that referenced
this pull request
Jan 31, 2025
* feat: Optimze CreateNamedStruct preserve dictionaries Instead of serializing the return data_type we just serialize the field names. The original implmentation was done as it lead to slightly simpler implementation, but it clear from apache#750 that this was the wrong choice and leads to issues with the physical data_type. * Support dictionary data_types in StructVector and MapVector * Add length checks
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Which issue does this PR close?
Closes #47.
Rationale for this change
In addition to the current
collect*methods that load results into memory in aVec<RecordBatch>this PR adds alternateexecute_stream*methods that return streams instead so that results don't have to be loaded into memory before being processed.What changes are included in this PR?
New
execute_streamandexecute_stream_partitionedmethods onDataFrame.Are there any user-facing changes?
Yes, new DataFrame methods.