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docs: fix sync-diff-inspector limitations in migration tools #23887

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docs: fix sync-diff-inspector limitations in migration tools #23887

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2 changes: 1 addition & 1 deletion migration-tools.md
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Expand Up @@ -83,7 +83,7 @@ This document introduces the user scenarios, supported upstreams and downstreams
- **Advantages**: Can be used to repair data in the scenario where a small amount of data is inconsistent
- **Limitation**:
- Online check is not supported for data migration between MySQL and TiDB.
- JSON, BIT, BINARY, BLOB and other types of data are not supported.
- Data type support varies by type. JSON, BLOB/VARBINARY, and BIT are supported. For FLOAT/DOUBLE and collation-related considerations, see [Restrictions of sync-diff-inspector](/sync-diff-inspector/sync-diff-inspector-overview.md).

@coderabbitai coderabbitai Bot Sep 16, 2026

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🎯 Functional Correctness | 🟡 Minor | ⚡ Quick win

🔎 Supported by static analysis

🏁 Script executed:

sed -n '72,95p' migration-tools.md
sed -n '45,70p' sync-diff-inspector/sync-diff-inspector-overview.md
sed -n '310,335p' sync-diff-inspector/sync-diff-inspector-overview.md

Repository: pingcap/docs

Length of output: 7736

Document the restrictions for JSON and BIT.

The linked restrictions document qualifies the current support claim: JSON string comparisons can produce false positives when collations or character sets differ, and BIT is validated only for MySQL-to-TiDB comparisons with widths 1, 8, 16, and 64. The current summary does not expose these limits.

Suggested replacement
Suggested change
- Data type support varies by type. JSON, BLOB/VARBINARY, and BIT are supported. For FLOAT/DOUBLE and collation-related considerations, see [Restrictions of sync-diff-inspector](/sync-diff-inspector/sync-diff-inspector-overview.md).
- Data type support varies by type. JSON is supported, but collation and character set differences for JSON string values can cause false positives. BLOB/VARBINARY are supported and compared byte-for-byte. BIT is supported for MySQL to TiDB comparisons for widths 1, 8, 16, and 64. For FLOAT/DOUBLE and additional collation considerations, see [Restrictions of sync-diff-inspector](/sync-diff-inspector/sync-diff-inspector-overview.md).


## Install tools using TiUP

Expand Down