expression: split multi valued index test

[hawkingrei]

What problem does this PR solve?

Issue Number: ref #44940

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]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: lance6716, wshwsh12

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[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2023-06-28 06:16:35.686948061 +0000 UTC m=+774761.088198509: ☑️ agreed by lance6716.
• 2023-06-28 06:22:02.51070479 +0000 UTC m=+775087.911955239: ☑️ agreed by wshwsh12.