viirya opened a new pull request, #19533:
URL: https://github.com/apache/datafusion/pull/19533
Optimize translate function by reusing HashMap and Vec buffers across all
rows instead of allocating new ones for each row.
Changes:
- Moved HashMap and Vec allocations outside the main loop
- Clear and reuse buffers for each row instead of reallocating
- Use explicit loops instead of chained iterators for better control
- Added benchmark to measure performance improvements
Optimization:
- Before: Allocated HashMap + 4 Vecs for every row
- After: Single set of reusable buffers cleared for each row
Benchmark Results:
- size=1024, str_len=8: 234.6 µs → 147.9 µs (37% faster)
- size=1024, str_len=32: 628.6 µs → 394.2 µs (37% faster)
- size=4096, str_len=8: 964.4 µs → 575.2 µs (40% faster)
- size=4096, str_len=32: 2.54 ms → 1.56 ms (39% faster)
The optimization shows exceptional 37-40% performance improvements across
all test cases. The HashMap reuse is particularly impactful since HashMap
creation/destruction has significant overhead with hashing, bucket allocation,
and internal bookkeeping. Combined with eliminating 4 Vec allocations per row,
this becomes the most significant optimization in this series.
## Which issue does this PR close?
<!--
We generally require a GitHub issue to be filed for all bug fixes and
enhancements and this helps us generate change logs for our releases. You can
link an issue to this PR using the GitHub syntax. For example `Closes #123`
indicates that this PR will close issue #123.
-->
- Closes #.
## Rationale for this change
<!--
Why are you proposing this change? If this is already explained clearly in
the issue then this section is not needed.
Explaining clearly why changes are proposed helps reviewers understand your
changes and offer better suggestions for fixes.
-->
## What changes are included in this PR?
<!--
There is no need to duplicate the description in the issue here but it is
sometimes worth providing a summary of the individual changes in this PR.
-->
## Are these changes tested?
<!--
We typically require tests for all PRs in order to:
1. Prevent the code from being accidentally broken by subsequent changes
2. Serve as another way to document the expected behavior of the code
If tests are not included in your PR, please explain why (for example, are
they covered by existing tests)?
-->
## Are there any user-facing changes?
<!--
If there are user-facing changes then we may require documentation to be
updated before approving the PR.
-->
<!--
If there are any breaking changes to public APIs, please add the `api
change` label.
-->
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
