statistics: reuse datum when to buildHist

[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)
• 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 #47371 (e23d2de) into master (a7d0a3a) will increase coverage by 0.3893%.
Report is 10 commits behind head on master.
The diff coverage is 100.0000%.

Additional details and impacted files

@@               Coverage Diff                @@
##             master     #47371        +/-   ##
================================================
+ Coverage   72.3231%   72.7125%   +0.3893%     
================================================
  Files          1352       1373        +21     
  Lines        400815     407271      +6456     
================================================
+ Hits         289882     296137      +6255     
- Misses        91754      92341       +587     
+ Partials      19179      18793       -386     

Flag	Coverage Δ
integration	38.7008% <100.0000%> (?)
unit	72.3153% <100.0000%> (-0.0078%)	⬇️

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

Components	Coverage Δ
dumpling	53.9913% <ø> (ø)
parser	84.7544% <ø> (-0.0108%)	⬇️
br	48.7421% <ø> (-4.3579%)	⬇️

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: qw4990, time-and-fate

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• OWNERS [qw4990,time-and-fate]

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[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2023-10-07 01:47:30.734762533 +0000 UTC m=+844048.321872684: ☑️ agreed by qw4990.
• 2023-10-07 03:45:14.181391041 +0000 UTC m=+851111.768501183: ☑️ agreed by time-and-fate.

[hawkingrei]

/retest

[hawkingrei]

/retest