planner: cherry pick two CTE related commit | tidb-test=pr/2145

[winoros]

What problem does this PR solve?

Issue Number: ref #44054, ref #43759

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 code

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

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• time-and-fate
• wjhuang2016

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[winoros]

/test check_dev-2

[ti-chi-bot]

@winoros: The specified target(s) for /test were not found.
The following commands are available to trigger required jobs:

• /test build
• /test check-dev
• /test check-dev2
• /test mysql-test
• /test unit-test

Use /test all to run all jobs.

In response to this:

/test check_dev-2

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 kubernetes/test-infra repository.

[winoros]

/test check-dev2

[winoros]

/merge

[ti-chi-bot]

This pull request has been accepted and is ready to merge.

Commit hash: 2120323