*: avoid copy in the SortSampleItems

[hawkingrei]

What problem does this PR solve?

Issue Number: ref #47275

Problem Summary:

What is changed and how it works?

Check List

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)

before

$ go test -benchmem -run=^$ -bench ^BenchmarkBuildHistAndTopN$ github.com/pingcap/tidb/pkg/statistics
goos: darwin
goarch: arm64
pkg: github.com/pingcap/tidb/pkg/statistics
BenchmarkBuildHistAndTopN-8            1        1363438291 ns/op        72031328 B/op    4000055 allocs/op

after

$ go test -benchmem -run=^$ -bench ^BenchmarkBuildHistAndTopN$ github.com/pingcap/tidb/pkg/statistics
goos: darwin
goarch: arm64
pkg: github.com/pingcap/tidb/pkg/statistics
BenchmarkBuildHistAndTopN-8            1        1352474167 ns/op        64027744 B/op    4000054 allocs/op

• No need to test

  • I checked and no code files have been changed.

Side effects

• Performance regression: Consumes more CPU
• Performance regression: Consumes more Memory
• Breaking backward compatibility

Documentation

• Affects user behaviors
• Contains syntax changes
• Contains variable changes
• Contains experimental features
• Changes MySQL compatibility

Release note

Please refer to Release Notes Language Style Guide to write a quality release note.

None

[codecov]

Codecov Report

Merging #48683 (9474b87) into master (26db590) will decrease coverage by 17.2115%.
Report is 10 commits behind head on master.
The diff coverage is 90.3508%.

Additional details and impacted files

@@                Coverage Diff                @@
##             master     #48683         +/-   ##
=================================================
- Coverage   71.0004%   53.7889%   -17.2115%     
=================================================
  Files          1367       1587        +220     
  Lines        404899     599562     +194663     
=================================================
+ Hits         287480     322498      +35018     
- Misses        97382     254474     +157092     
- Partials      20037      22590       +2553     

Flag	Coverage Δ
integration	35.2820% <60.5263%> (?)
unit	71.2784% <85.5263%> (+0.2779%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Components	Coverage Δ
dumpling	53.9663% <ø> (ø)
parser	∅ <ø> (∅)
br	55.6365% <59.2592%> (+2.5557%)	⬆️

[hawkingrei]

/retest

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: qw4990, winoros

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [qw4990,winoros]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2023-11-20 01:36:50.796753354 +0000 UTC m=+195439.461979549: ☑️ agreed by winoros.
• 2023-11-20 03:37:14.98314885 +0000 UTC m=+202663.648375045: ☑️ agreed by qw4990.

[hawkingrei]

/hold

waiting for the benchmark test

[hawkingrei]

/unhold

[hawkingrei]

/test all

[hawkingrei]

/retest

[hawkingrei]

/test all

[hawkingrei]

/cherrypick release-6.5
/cherrypick release-7.1

[ti-chi-bot]

@hawkingrei: new pull request created to branch release-6.5: #49535.

In response to this:

/cherrypick release-6.5
/cherrypick release-7.1

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the ti-community-infra/tichi repository.

[ti-chi-bot]

@hawkingrei: new pull request created to branch release-7.1: #49536.

In response to this:

/cherrypick release-6.5
/cherrypick release-7.1

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the ti-community-infra/tichi repository.