*: Add metrics for index lookup push-down

[lcwangchao]

What problem does this PR solve?

Issue Number: close #64485

What changed and how does it work?

Add some metrics for index lookup push down:

• IndexLookUp OPS The OPS of IndexLookUp, it contains the index-lookup-pushdown OPS for both executor and tasks.
• IndexLookUp Duration The IndexLookUpExecutor duration if push down is enabled
• IndexLookUp Rows The hint and miss rows for index lookup pushdown
• IndexLookUp PushDown Row Num The bucket of query rows in each IndexLookUpExecutor if push down is enabled

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

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 73.4259%. Comparing base (bd6aa86) to head (a37d39f).
⚠️ Report is 1 commits behind head on master.

Additional details and impacted files

@@               Coverage Diff                @@
##             master     #64487        +/-   ##
================================================
+ Coverage   72.6891%   73.4259%   +0.7368%     
================================================
  Files          1866       1867         +1     
  Lines        506286     506769       +483     
================================================
+ Hits         368015     372100      +4085     
+ Misses       115899     112486      -3413     
+ Partials      22372      22183       -189     

Flag	Coverage Δ
integration	41.8092% <92.3076%> (?)
unit	72.5678% <100.0000%> (+0.3049%)	⬆️

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

Components	Coverage Δ
dumpling	52.8700% <ø> (+0.1132%)	⬆️
parser	∅ <ø> (∅)
br	46.2438% <ø> (+0.0676%)	⬆️

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[lcwangchao]

/retest

[cfzjywxk]

LGTM

[lcwangchao]

/retest

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: cfzjywxk, you06
Once this PR has been reviewed and has the lgtm label, please assign zimulala for approval. For more information see the Code Review Process.
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[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2025-11-17 08:47:40.30021847 +0000 UTC m=+1296709.743248359: ☑️ agreed by cfzjywxk.
• 2025-11-17 10:04:01.570409598 +0000 UTC m=+1301291.013439477: ☑️ agreed by you06.