# Predicate Push Down (Continue...)


![left](./student-guide/diagram/16-predicate-pushdown-02-01.png)

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The modify SQL logic is changed to the INNER JOIN method, and the intersection calculation needs to be performed, because in addition to the predicate of the association condition, there is also a separate filter for the related table. In order to improve the efficiency of TiDB Server aggregation calculation and reduce unnecessary computation overhead, t1.val > 11 and t2.val > 22 can be pushdown. The TiKV of the node is calculated. 

In the process of predicate pushing down, inefficient aggregate computation and IO consumption are reduced through outer join to inner join, and OUT JOIN is converted to INNER JOIN.