planner, sessionctx: skip wide type columns such as JSON when collecting statistics (#44653) | tidb-test=pr/2158

[ti-chi-bot]

This is an automated cherry-pick of #44653

What problem does this PR solve?

Issue Number: close #44725

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

Please refer to Release Notes Language Style Guide to write a quality release note.

None

[qw4990]

Please resolve conflicts:

sessionctx/variable/tidb_vars.go:879:1: syntax error: unexpected <<, expected name
sessionctx/variable/tidb_vars.go:886:107: invalid character U+0023 '#'
sessionctx/variable/tidb_vars.go:886:114: syntax error: unexpected ) after top level declaration

[xuyifangreeneyes]

/test check-dev

[xuyifangreeneyes]

/test mysql-test

[xuyifangreeneyes]

/test check-dev

[xuyifangreeneyes]

/test mysql-test

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: chrysan, qw4990

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• OWNERS [chrysan,qw4990]

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[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2023-06-21 03:22:56.57038795 +0000 UTC m=+159541.971638384: ☑️ agreed by qw4990.
• 2023-06-21 06:05:02.920229497 +0000 UTC m=+169268.321479946: ☑️ agreed by chrysan.