perf: make cloning SessionState faster by sharing most state behind an Arc - #24560
Merged
Conversation
Contributor
Author
|
@alamb could you start the |
tschwarzinger
changed the title
SessionState faster by sharing must state behind an ArcSessionState faster by sharing most state behind an Arc
Contributor
Author
|
@jonathanc-n I hope it's ok that I've submitted a PR for this even though you're assigned. Happy to hear your feedback! |
tschwarzinger
changed the title
SessionState faster by sharing most state behind an ArcSessionState faster by sharing most state behind an Arc
Contributor
|
run benchmark sql_planner |
|
🤖 Benchmark running (GKE) | trigger CPU Details (lscpu)Comparing planner-perf-1 (d6dd73f) to f1f0449 (merge-base) diff Run configurationrun benchmark sql_plannerResults will be posted here when complete File an issue against this benchmark runner |
Codecov Report❌ Patch coverage is
Additional details and impacted files@@ Coverage Diff @@
## main #24560 +/- ##
==========================================
+ Coverage 81.27% 81.34% +0.07%
==========================================
Files 1116 1117 +1
Lines 395017 397501 +2484
Branches 395017 397501 +2484
==========================================
+ Hits 321055 323363 +2308
- Misses 55166 55223 +57
- Partials 18796 18915 +119 ☔ View full report in Codecov by Harness. 🚀 New features to boost your workflow:
|
|
🤖 Benchmark completed (GKE) | trigger Instance: Comparing planner-perf-1 (d6dd73f) to f1f0449 (merge-base) diff Run configurationrun benchmark sql_plannerCPU Details (lscpu)Details
Resource Usagesql_planner — base (merge-base)
sql_planner — branch
File an issue against this benchmark runner |
Contributor
|
Nice, looks like some substantial wins |
Contributor
|
run benchmark sql_planner |
|
🤖 Benchmark running (GKE) | trigger CPU Details (lscpu)Comparing planner-perf-1 (d6dd73f) to f1f0449 (merge-base) diff Run configurationrun benchmark sql_plannerResults will be posted here when complete File an issue against this benchmark runner |
Dandandan
approved these changes
Aug 21, 2026
|
🤖 Benchmark completed (GKE) | trigger Instance: Comparing planner-perf-1 (d6dd73f) to f1f0449 (merge-base) diff Run configurationrun benchmark sql_plannerCPU Details (lscpu)Details
Resource Usagesql_planner — base (merge-base)
sql_planner — branch
File an issue against this benchmark runner |
Contributor
|
Amazing 🚀 ! |
Contributor
|
Thank you @tschwarzinger and @Dandandan |
alamb
reviewed
Aug 24, 2026
| /// [`SessionContext::state`]. | ||
| /// | ||
| /// [`SessionContext::state`]: crate::execution::context::SessionContext::state | ||
| execution_props: ExecutionProps, |
This file contains hidden or 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
5 participants
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?
Rationale for this change
Improve planner performance. See (#20495)
The solution I came up with is a bit different to the one discussed in the issue. Instead of avoiding cloning
SessionStatewe just make it cheap to clone it by wrapping most of the state in anArc. Cloning is only necessary when mutating the inner session state, if we're not the sole reference (Arc::make_mutas dicussed in the issue).I initially tried to wrap the entire
SessionStatein an Arc but we still need copying if we're not the only reference, asexecution_propsare changed for each query.What changes are included in this PR?
SessionStateInnerout of the session state and share it behind anArc<SessionStateInner>Are these changes tested?
Yes with existing tests
Are there any user-facing changes?
No, except faster performance