# The `Key-Value` Form of the Table
![`smart`](ClusteredIndexes02_aa_004_20230922.png)
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In the "Introduction to TiDB" course, we learned that TiDB databases store relational database tables in the form of `key-value` pair entries in TiKV cluster. Therefore, we consider the `ID (PK)` column (i.e., the primary key) as the key in TiKV, and the set formed by the other columns as the value in TiKV.