planner: fix should not use point get plan (#21124)

[ti-srebot]

cherry-pick #21124 to release-4.0

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What problem does this PR solve?

Issue Number: close #21123 , close #21204

Problem Summary:

In MySQL string convert to numbers it will use number prefix to convert to number, for example:

'asdf' => 0
'123asdf' => 123

So if we create a table like create table t (id varchar(10) primary key), then insert ('asdf'), ('1asdf') into this table. When we execute a query like:

select * from t where id = 0;

the plan should be convert column id into int and compare with number 0, so we should get 'asdf' as the result. But in TiDB it will convert number 0 to string '0' and use point get plan to fetch id = '0' rows, so we will get an empty set result.

What is changed and how it works?

What's Changed:

Add type check for TryFastPlan, if column type is string like and in or = value is number just return empty plan.

Related changes

• Need to cherry-pick to the release branch

Check List

Tests

• Unit test
• Integration test

Side effects

• Performance regression
  • Consumes more CPU

Release note

• planner: fix wrong point get plan generation in fast plan code path

[ti-srebot]

/run-all-tests

[ti-srebot]

@blacktear23 you're already a collaborator in bot's repo.

[wjhuang2016]

LGTM

[lzmhhh123]

LGTM

[lzmhhh123]

/merge

[ti-srebot]

Sorry @lzmhhh123, this branch cannot be merged without an approval of release maintainers

[SunRunAway]

/merge

[ti-srebot]

Your auto merge job has been accepted, waiting for:

• 20889
• 21273
• 20998

[ti-srebot]

/run-all-tests