parser,executor: Add current_tso() function

[AndrewDi]

What problem does this PR solve?

Issue Number: close #37035

Problem Summary:

What is changed and how it works?

Add new scalar function current_tso()

Check List

Tests

• [x] Unit test
• [ ] Integration test
• [x] Manual test (add detailed scripts or steps below)
• [ ] No code

begin;
select current_tso();
commit;

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• ngaut
• tiancaiamao

To complete the pull request process, please ask the reviewers in the list to review by filling /cc @reviewer in the comment. After your PR has acquired the required number of LGTMs, you can assign this pull request to the committer in the list by filling /assign @committer in the comment to help you merge this pull request.

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

Reviewer can indicate their review by submitting an approval review. Reviewer can cancel approval by submitting a request changes review.

[AndrewDi]

/run-unit-test

[AndrewDi]

/run-mysql-test

[AndrewDi]

@tiancaiamao mysql-test fail....I didn't touch this one

[tiancaiamao]

PTAL @bb7133

[SunRunAway]

@AndrewDi Refer to https://docs.pingcap.com/tidb/dev/tidb-functions, cloud you name it "tidb_current_tso"? Thanks.

[AndrewDi]

@AndrewDi Refer to https://docs.pingcap.com/tidb/dev/tidb-functions, cloud you name it "tidb_current_tso"? Thanks.

I think select current_tso() would be more close to the mysql original ecosystem...

[SunRunAway]

@AndrewDi Refer to https://docs.pingcap.com/tidb/dev/tidb-functions, cloud you name it "tidb_current_tso"? Thanks.

I think select current_tso() would be more close to the mysql original ecosystem...

I don't get why it is more close to the mysql original ecosystem. Could you explain more?

IMO, it is a TiDB-specific function, and we already have many functions named starting with "tidb_", such as "TIDB_PARSE_TSO(num)" (see https://docs.pingcap.com/tidb/dev/tidb-functions). It is more intuitive for the user to first use "TIDB_CURRENT_TSO" to get the TSO, and then use "TIDB_PARSE_TSO" to parse the TSO.

[AndrewDi]

@SunRunAway rename to tidb_current_tso

[AndrewDi]

@SunRunAway PTAL...

[tiancaiamao]

/merge

[ti-chi-bot]

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

Commit hash: 549eb42f1251d36f7c350223c159a127bc0c6211

[sre-bot]

TiDB MergeCI notify

🔴 Bad News! New failing [1] after this pr merged. These new failed integration tests seem to be caused by the current PR, please try to fix these new failed integration tests, thanks!

CI Name	Result	Duration	Compare with Parent commit
idc-jenkins-ci/integration-cdc-test	🟥 failed 1, success 36, total 37	24 min	New failing
idc-jenkins-ci-tidb/tics-test	✅ all 1 tests passed	15 min	Fixed
idc-jenkins-ci-tidb/integration-ddl-test	🟢 all 6 tests passed	29 min	Existing passed
idc-jenkins-ci-tidb/integration-common-test	🟢 all 17 tests passed	10 min	Existing passed
idc-jenkins-ci-tidb/common-test	🟢 all 11 tests passed	8 min 54 sec	Existing passed
idc-jenkins-ci-tidb/sqllogic-test-2	🟢 all 28 tests passed	4 min 44 sec	Existing passed
idc-jenkins-ci-tidb/sqllogic-test-1	🟢 all 26 tests passed	4 min 42 sec	Existing passed
idc-jenkins-ci-tidb/mybatis-test	🟢 all 1 tests passed	3 min 23 sec	Existing passed
idc-jenkins-ci-tidb/integration-compatibility-test	🟢 all 1 tests passed	2 min 55 sec	Existing passed
idc-jenkins-ci-tidb/plugin-test	🟢 build success, plugin test success	4min	Existing passed