sync-diff-inspector: add sql-hint-use-index in config for automatically apply hint in check SQL

[joechenrh]

What problem does this PR solve?

Issue Number: close #836

Add hint /*+ USE_INDEX(dbName.tblName, indexName) */ to force index scan in checksum SQL. Note this index hint is only applied on TiDB source.

How to use?

[data-sources]
[data-sources.source]
host = "127.0.0.1"
port = 4000
user = "root"
password = ""

# Automatically detects and applies existing indexes, only applies on TiDB source.
sql-hint-use-index = "auto"

What is changed and how it works?

In each chunk, we will store the column names of the index used to split chunks. These column names will be used to match exact index name to build the index hint.

The reason we store column names rather than store index name directly is to avoid different index names between upstream and downstream.

For example:

• upstream has table t1(id int, col1 int, unique index i1(id, col1))
• downstream has table t1(id int, col1 int, unique index i2(id, col1))

Check List

Tests

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

Code changes

• Has exported function/method change
• Has exported variable/fields change
• Has interface methods change
• Has persistent data change

Side effects

• Possible performance regression
• Increased code complexity
• Breaking backward compatibility

Related changes

• Need to cherry-pick to the release branch
• Need to update the documentation
• Need to be included in the release note

[CLAassistant]

All committers have signed the CLA.

[joechenrh]

/retest

[joechenrh]

/retest

[joechenrh]

/release-note-none

[joechenrh]

/retest

[joechenrh]

/retest

[joechenrh]

/cc @kennytm

[kennytm]

rest lgtm

[kennytm]

Suggested change

	require.Equal(t, len(node.ChunkRange.IndexColumnNames), len(testColNames))
	for i, c := range testColNames {
	require.Equal(t, c, node.ChunkRange.IndexColumnNames[i])
	}
	require.Equal(t, node.ChunkRange.IndexColumnNames, testColNames)

require.Equal uses reflect.DeepEqual which supports slices.

[kennytm]

Suggested change

	indexHint = fmt.Sprintf("/*+ USE_INDEX(`%s`.`%s`, `%s`) */",
	matchSource.OriginSchema,
	matchSource.OriginTable,
	index.Name.L,
	)
	indexHint = fmt.Sprintf("/*+ USE_INDEX(%s, %s) */",
	dbutil.TableName(matchSource.OriginSchema, matchSource.OriginTable),
	dbutil.ColumnName(index.Name.O),
	)

(yeah it is not a column but whatever)

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: kennytm

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• OWNERS [kennytm]

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[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2025-03-06 07:58:43.916733346 +0000 UTC m=+514837.045653085: ☑️ agreed by kennytm.

[kennytm]

/retest