doc: update window function design doc

[SeaRise]

What problem does this PR solve?

Issue Number: close #5781

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

None

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• gengliqi
• ywqzzy

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[gengliqi]

- Compared with TiDB, currently only row_number, rank, dense_rank functions are supported.
This sentence also needs to update.

[gengliqi]

LGTM

[SeaRise]

/merge

[ti-chi-bot]

@SeaRise: It seems you want to merge this PR, I will help you trigger all the tests:

/run-all-tests

You only need to trigger /merge once, and 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.

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[ti-chi-bot]

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

Commit hash: f3fcc1b

[ti-chi-bot]

@SeaRise: Your PR was out of date, I have automatically updated it for you.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

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.

[sre-bot]

Coverage for changed files

no c/c++ source change detected

Coverage summary

Functions  MissedFunctions  Executed  Lines   MissedLines  Cover
18629      8331             55.28%    215418  85844        60.15%

full coverage report (for internal network access only)