# Summary Of Multi-Table Joins

+ best practices
  + When joining, we need to use a small table to drive a large table
  + Predicate column that participate in Join are suggested to be indexed

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summed

We introduced a best practice for tuning join: small tables drive large tables, and associated column need to be indexed.

We also introduced the four technologies and application scenario of joins in TiDB. We can solve the performance problems related to such join by paying attention to actual use and using them according to actual business requirements.