planner: use TxnCtx.InfoSchema to prevent schema inconsistency (#49947)

[ti-chi-bot]

This is an automated cherry-pick of #49947

What problem does this PR solve?

Issue Number: ref #41622

close #49751

Problem Summary:

What changed and how does it work?

The result of sctx.GetInfoSchema().(infoschema.InfoSchema) is not stable if the caller side is not in a transaction && snapshot_ts is not set, it just get the latest InfoSchema:

tidb/pkg/session/session.go

Lines 4052 to 4074 in c20874e

	func (s *session) GetInfoSchema() sessionctx.InfoschemaMetaVersion {
	vars := s.GetSessionVars()
	var is infoschema.InfoSchema
	if snap, ok := vars.SnapshotInfoschema.(infoschema.InfoSchema); ok {
	logutil.BgLogger().Info("use snapshot schema", zap.Uint64("conn", vars.ConnectionID), zap.Int64("schemaVersion", snap.SchemaMetaVersion()))
	is = snap
	} else {
	vars.TxnCtxMu.Lock()
	if vars.TxnCtx != nil {
	if tmp, ok := vars.TxnCtx.InfoSchema.(infoschema.InfoSchema); ok {
	is = tmp
	}
	}
	vars.TxnCtxMu.Unlock()
	}
	if is == nil {
	is = domain.GetDomain(s).InfoSchema()
	}
	// Override the infoschema if the session has temporary table.
	return temptable.AttachLocalTemporaryTableInfoSchema(s, is)
	}

Check List

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)
• No need to test

  • I checked and no code files have been changed.

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.

planner: use TxnCtx.InfoSchema to prevent schema inconsistency

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: hawkingrei, winoros

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• OWNERS [hawkingrei,winoros]

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[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2024-01-23 14:12:19.070143288 +0000 UTC m=+883580.634440988: ☑️ agreed by hawkingrei.
• 2024-01-23 14:14:56.463896194 +0000 UTC m=+883738.028193897: ☑️ agreed by winoros.

[codecov]

Codecov Report

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The diff coverage is n/a.

Additional details and impacted files

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