planner, executor: add stale read compatibility for temporary table

[lcwangchao]

What problem does this PR solve?

Temporary table should not perform stale read

What is changed and how it works?

Add member variable ExplicitStaleness to builder to mark if this query statement should use stale read explicitly. If the txn is staleness or query is marked staleness, temporary table read should be fail.

Related changes

N/A

Check List

Tests

• Unit test

Side effects

N/A

Release note

• No release note

[ti-srebot]

No release note, Please follow https://github.com/pingcap/community/blob/master/contributors/release-note-checker.md

[ti-srebot]

No release note, Please follow https://github.com/pingcap/community/blob/master/contributors/release-note-checker.md

[lcwangchao]

/run-check_dev_2

[ti-chi-bot]

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[xhebox]

What about IsStaleness instead of ExplicitStaleness? I am OK to ExplicitStaleness, though. Will approve anyway after the response.

[lcwangchao]

What about IsStaleness instead of ExplicitStaleness? I am OK to ExplicitStaleness, though. Will approve anyway after the response.

@xhebox The word Explicit means that it uses stale read explicitly in the query statement. So ExplicitStaleness can be a false value when we just use START TRANSACTION READ ONLY AS OF TIMESTAMP... which is still a stale read. I think it may be a bit more clear to indicate what the variable means.

[xhebox]

@icditwang But it will be true in the next begin or select * .. without as of.

[ti-chi-bot]

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• djshow832
• xhebox

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[xhebox]

/merge

[ti-chi-bot]

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

Commit hash: 4bfdcdc

[nolouch]

Does it need to pick to 5.1?

[ti-srebot]

cherry pick to release-5.1 in PR #25786

[djshow832]

Does it need to pick to 5.1?

The temporary table is not GA in 5.1, it will be GA in 5.1.1. We are cherry-picking it to release-5.1. @nolouch