*: Allow Point_Get during DDL with Global Index (#56382)

[ti-chi-bot]

This is an automated cherry-pick of #56382

What problem does this PR solve?

Issue Number: ref #55819 , ref #45133 , close #56819

Problem Summary:
During DDL that affects Global Index, the PointGet access method is blocked, which may cause temporary bad query plans during partitioning management commands, like DROP/TRUNCATE/REORGANIZE PARTITION.

What changed and how does it work?

Allow PointGet, by filter away the partitions that should not be seen (like when the cleanup of the global index is ongoing).

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

Attention: Patch coverage is 85.58559% with 16 lines in your changes missing coverage. Please review.

Please upload report for BASE (release-8.4@27e78ae). Learn more about missing BASE report.

Additional details and impacted files

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Flag	Coverage Δ
integration	36.8127% <62.1621%> (?)
unit	72.4831% <74.7747%> (?)

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

Components	Coverage Δ
dumpling	52.9478% <0.0000%> (?)
parser	∅ <0.0000%> (?)
br	52.3414% <0.0000%> (?)

[bb7133]

LGTM

[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2024-10-25 16:46:43.325158261 +0000 UTC m=+22716.164313830: ☑️ agreed by mjonss.
• 2024-10-25 17:44:21.268834869 +0000 UTC m=+26174.107990410: ☑️ agreed by bb7133.

[bb7133]

/retest

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: bb7133, mjonss, tangenta, winoros

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Needs approval from an approver in each of these files:

• OWNERS [bb7133,mjonss,tangenta,winoros]
• pkg/ddl/OWNERS [tangenta]
• pkg/meta/OWNERS [tangenta]
• pkg/planner/OWNERS [winoros]

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