planner: fix incorrect maintenance of handleColHelper for recursive CTE

[time-and-fate]

What problem does this PR solve?

Issue Number: close #55666

Problem Summary:

If the recursive part of a CTE references tables other than the CTE itself, the b.handleHelper won't be correctly cleared during buildRecursiveCTE().

It's because this function relies on an error from buildSelect() or buildSetOpr() to recognize the boundary between the seed part and the recursive part. But b.handleHelper won't be cleared when an error happens.

When this happens, there will be some wrong and redundant entries in b.handleHelper, which makes users of this field like buildDelete() get the wrong result or panic.

What changed and how does it work?

Since this PR needs to be cherry-picked, I can't change too many.

• In buildRecursiveCTE(), clear the b.handleHelper if an error is returned from buildSelect() or buildSetOpr().
• Try to make the b.handleHelper more clear for recursive CTE:
  • Now tryBuildCTE() will always push an entry into handleHelper when successful.
  • Now buildRecursiveCTE() will always push an entry into handleHelper when successful.

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 56.1953%. Comparing base (e9124dd) to head (c9d0d47).
Report is 4 commits behind head on master.

Additional details and impacted files

@@                Coverage Diff                @@
##             master     #55732         +/-   ##
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- Coverage   72.8514%   56.1953%   -16.6561%     
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  Files          1601       1729        +128     
  Lines        445302     622110     +176808     
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+ Hits         324409     349597      +25188     
- Misses       100894     248845     +147951     
- Partials      19999      23668       +3669     

Flag	Coverage Δ
integration	37.4003% <100.0000%> (?)
unit	72.1316% <100.0000%> (+0.1704%)	⬆️

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

Components	Coverage Δ
dumpling	52.9567% <ø> (ø)
parser	∅ <ø> (∅)
br	52.8045% <ø> (+7.0278%)	⬆️

[XuHuaiyu]

Please add a description of how to handle CTE in the comments for the handleHelper attribute.

[time-and-fate]

/retest

[Rustin170506]

Looks good to me. Thanks! 👍

[Rustin170506]

Can I ask why we need to remove this?

[time-and-fate]

The popMap() here is moved right after b.buildSelect() and b.buildSetOpr() in this function.
This should make it more clear and explicit that we directly drop the entries pushed by them.

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: Rustin170506, winoros

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• OWNERS [Rustin170506,winoros]
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[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2024-09-04 06:59:30.400385092 +0000 UTC m=+427694.918438014: ☑️ agreed by Rustin170506.
• 2024-09-05 17:34:32.032588724 +0000 UTC m=+552196.550641648: ☑️ agreed by winoros.

[time-and-fate]

/retest

[time-and-fate]

/retest

[ti-chi-bot]

In response to a cherrypick label: new pull request created to branch release-6.5: #55896.

[ti-chi-bot]

In response to a cherrypick label: new pull request created to branch release-7.1: #55897.

[ti-chi-bot]

In response to a cherrypick label: new pull request created to branch release-7.5: #55898.

[ti-chi-bot]

In response to a cherrypick label: new pull request created to branch release-8.1: #55899.