# Additional Considerations

+ Avoid using **`sync-diff-inspector`** to check data during business hours
+ Add collation to the **`sync-diff-inspector`** configuration file if the collation configuration between upstream and downstream differs
+ **`sync-diff-inspector`** divides data into chunks first according to `TiDB` statistics, which may not always be up-to-dated.
+ The generated fixing `SQL` scripts should be used as a reference only

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`sync-diff-inspector` consumes a certain amount of server resources when checking data. Avoid using `sync-diff-inspector` to check data during peak business hours.

Before comparing the data in `MySQL` with that in `TiDB`, pay attention to the collation configuration of the tables. If the primary key or unique key is the `varchar` type and the collation configuration in `MySQL` differs from that in `TiDB`, the final check result might be incorrect because of the collation issue. You need to add collation to the `sync-diff-inspector` configuration file.

`sync-diff-inspector` divides data into chunks first according to `TiDB` statistics and you need to guarantee the accuracy of the statistics. You can manually run the `analyze table {table_name}` command when the `TiDB` server's workload is light.

The generated `SQL` file is only used as a reference for repairing data, and you need to confirm it before executing these `SQL` statements to repair data.