Support collation in position function

[xzhangxian1008]

What problem does this PR solve?

Issue Number: close #9377
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

Support collation in `position` function

[xzhangxian1008]

/cc @windtalker @yibin87

[yibin87]

Generally, use ++variable instead of variable++ unless we do need to keep the unchanged value.

[xzhangxian1008]

LibCASCIICaseSensitiveStringSearcher

Modern compiler should know if it needs to create a tmp object for variable++, so I think there is no difference between variable++ and ++variable.

[xzhangxian1008]

/cc @windtalker

[windtalker]

lgtm

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: windtalker, yibin87

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[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2024-11-21 01:12:35.471204313 +0000 UTC m=+80543.090858829: ☑️ agreed by yibin87.
• 2024-11-22 12:33:35.903126019 +0000 UTC m=+207803.522780546: ☑️ agreed by windtalker.

[ti-chi-bot]

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/run-all-tests

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[xzhangxian1008]

/retest

[xzhangxian1008]

/cherrypick release-8.1

[ti-chi-bot]

@xzhangxian1008: once the present PR merges, I will cherry-pick it on top of release-8.1 in the new PR and assign it to you.

In response to this:

/cherrypick release-8.1

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[xzhangxian1008]

/retest

[xzhangxian1008]

/retest

[ti-chi-bot]

@xzhangxian1008: new pull request created to branch release-8.1: #9669.

In response to this:

/cherrypick release-8.1

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 ti-community-infra/tichi repository.