tiflash: polish the format of dt_compression_level

[shichun-0415]

First-time contributors' checklist

• I've signed Contributor License Agreement that's required for repo owners to accept my contribution.

What is changed, added or deleted? (Required)

Polish the format of dt_compression_level for better readability.

Which TiDB version(s) do your changes apply to? (Required)

Tips for choosing the affected version(s):

By default, CHOOSE MASTER ONLY so your changes will be applied to the next TiDB major or minor releases. If your PR involves a product feature behavior change or a compatibility change, CHOOSE THE AFFECTED RELEASE BRANCH(ES) AND MASTER.

For details, see tips for choosing the affected versions.

• master (the latest development version)
• v6.6 (TiDB 6.6 versions)
• v6.5 (TiDB 6.5 versions)
• v6.4 (TiDB 6.4 versions)
• v6.1 (TiDB 6.1 versions)
• v5.4 (TiDB 5.4 versions)
• v5.3 (TiDB 5.3 versions)
• v5.2 (TiDB 5.2 versions)
• v5.1 (TiDB 5.1 versions)
• v5.0 (TiDB 5.0 versions)

What is the related PR or file link(s)?

• This PR is translated from: update tiflash-configuration.md docs-cn#11425
• Other reference link(s):

Do your changes match any of the following descriptions?

• Delete files
• Change aliases
• Need modification after applied to another branch
• Might cause conflicts after applied to another branch

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• Oreoxmt

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[Oreoxmt]

LGTM

[shichun-0415]

/status LGT2

[shichun-0415]

/merge

[ti-chi-bot]

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

Commit hash: d4db691

[ti-chi-bot]

In response to a cherrypick label: new pull request could not be created: failed to create pull request against pingcap/docs#release-6.1 from head ti-chi-bot:cherry-pick-12254-to-release-6.1: the GitHub API request returns a 403 error: {"message":"You have exceeded a secondary rate limit and have been temporarily blocked from content creation. Please retry your request again later.","documentation_url":"https://docs.github.com/rest/overview/resources-in-the-rest-api#secondary-rate-limits"}

[ti-chi-bot]

In response to a cherrypick label: new pull request could not be created: failed to create pull request against pingcap/docs#release-6.3 from head ti-chi-bot:cherry-pick-12254-to-release-6.3: the GitHub API request returns a 403 error: {"message":"You have exceeded a secondary rate limit and have been temporarily blocked from content creation. Please retry your request again later.","documentation_url":"https://docs.github.com/rest/overview/resources-in-the-rest-api#secondary-rate-limits"}

[ti-chi-bot]

In response to a cherrypick label: new pull request could not be created: failed to create pull request against pingcap/docs#release-6.4 from head ti-chi-bot:cherry-pick-12254-to-release-6.4: the GitHub API request returns a 403 error: {"message":"You have exceeded a secondary rate limit and have been temporarily blocked from content creation. Please retry your request again later.","documentation_url":"https://docs.github.com/rest/overview/resources-in-the-rest-api#secondary-rate-limits"}

[ti-chi-bot]

In response to a cherrypick label: new pull request could not be created: failed to create pull request against pingcap/docs#release-6.5 from head ti-chi-bot:cherry-pick-12254-to-release-6.5: the GitHub API request returns a 403 error: {"message":"You have exceeded a secondary rate limit and have been temporarily blocked from content creation. Please retry your request again later.","documentation_url":"https://docs.github.com/rest/overview/resources-in-the-rest-api#secondary-rate-limits"}

[shichun-0415]

/cherrypick release-6.1

[ti-chi-bot]

@shichun-0415: new pull request could not be created: failed to create pull request against pingcap/docs#release-6.1 from head ti-chi-bot:cherry-pick-12254-to-release-6.1: the GitHub API request returns a 403 error: {"message":"You have exceeded a secondary rate limit and have been temporarily blocked from content creation. Please retry your request again later.","documentation_url":"https://docs.github.com/rest/overview/resources-in-the-rest-api#secondary-rate-limits"}

In response to this:

/cherrypick release-6.1

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.

[shichun-0415]

/cherrypick release-6.1
/cherrypick release-6.3
/cherrypick release-6.4
/cherrypick release-6.5

[ti-chi-bot]

@shichun-0415: new pull request created to branch release-6.1: #12325.

In response to this:

/cherrypick release-6.1
/cherrypick release-6.3
/cherrypick release-6.4
/cherrypick release-6.5

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]

@shichun-0415: new pull request created to branch release-6.3: #12327.

In response to this:

/cherrypick release-6.1
/cherrypick release-6.3
/cherrypick release-6.4
/cherrypick release-6.5

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]

@shichun-0415: new pull request created to branch release-6.4: #12329.

In response to this:

/cherrypick release-6.1
/cherrypick release-6.3
/cherrypick release-6.4
/cherrypick release-6.5

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]

@shichun-0415: new pull request created to branch release-6.5: #12331.

In response to this:

/cherrypick release-6.1
/cherrypick release-6.3
/cherrypick release-6.4
/cherrypick release-6.5

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.