perf: Stop performing deep copies when CometScan source is an exchange #1097
+30
−4
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
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Outdated suggestions cannot be applied.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?
N/A
Rationale for this change
Because our current Parquet decoding logic reuses mutable buffers, we have to be careful to perform a deep copy before calling operators that could cache data. We do this by wrapping ScanExec in a CopyExec.
However, we use ScanExec both for reading from Parquet scans and also for reading from exchanges (broadcast and shuffle). We only need to perform deep copies in the Parquet case.
What changes are included in this PR?
Use
CopyMode::UnpackOrCloneinstead ofCopyMode::UnpackOrDeepCopywhen wrapping aCometScanthat is reading from an exchange.How are these changes tested?
Existing tests.