executor: fix wrong result of delete multiple tables using left join (#33055)

[ti-srebot]

cherry-pick #33055 to release-5.4
You can switch your code base to this Pull Request by using git-extras:

# In tidb repo:
git pr https://github.com/pingcap/tidb/pull/33123

After apply modifications, you can push your change to this PR via:

git push [email protected]:ti-srebot/tidb.git pr/33123:release-5.4-2dd0074e4ece

---

Signed-off-by: guo-shaoge [email protected]

What problem does this PR solve?

Issue Number: close #31321

Problem Summary:
delete from t1, t2 using t1 left join t2 on t1.c1 = t2.c1;

row of t1: (1)
row of t2: (2)
The join result will be (1, null). 1 in t1 is matched, and no row in t2 is matched. So row in t1 should be deleted, while no row in t2 should be deleted.

But the original implementation didn't check if the row in t2 is matched or not, just delete it directly, which cause the wrong result.

What is changed and how it works?

If a row is not matched in outer join, the rowid of the join result will be NULL, we use this to decide if we can delete row.

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

executor: fix wrong result of delete multiple tables using left join

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• winoros
• wshwsh12

To complete the pull request process, please ask the reviewers in the list to review by filling /cc @reviewer in the comment.
After your PR has acquired the required number of LGTMs, you can assign this pull request to the committer in the list by filling /assign @committer in the comment to help you merge this pull request.

The full list of commands accepted by this bot can be found here.

Reviewer can indicate their review by submitting an approval review.
Reviewer can cancel approval by submitting a request changes review.

[ti-srebot]

/run-all-tests

[ti-srebot]

@guo-shaoge you're already a collaborator in bot's repo.

[guo-shaoge]

/merge

[ti-chi-bot]

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

Commit hash: 7bfee1a

[sre-bot]

Code Coverage Details: https://codecov.io/github/pingcap/tidb/commit/7bfee1a714bcb18bcda8cdbac0aee3d51f0a76e1