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.

[yibin87]

LGTM

[xzhangxian1008]

/cc @windtalker

[windtalker]

lgtm

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

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

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

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [windtalker,yibin87]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[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]

@xzhangxian1008: Your PR was out of date, I have automatically updated it for you.

At the same time I will also trigger all tests for you:

/run-all-tests

trigger some heavy tests which will not run always when PR updated.

If the CI test fails, you just re-trigger the test that failed and the bot will merge the PR for you after the CI passes.

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.

[ti-chi-bot]

@xzhangxian1008: The following test failed, say /retest to rerun all failed tests or /retest-required to rerun all mandatory failed tests:

Test name	Commit	Details	Required	Rerun command
pull-integration-test	4c86a97	link	true	/test pull-integration-test

Full PR test history. Your PR dashboard.

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. I understand the commands that are listed here.