# TiFlash Features
+ It’s a columnar storage
+ Joins TiDB cluster as Raft Learner
+ With engine smart selection, supplements TiDB with OLAP capability
![left](./student-guide/diagram/TiDBClusterStorageWithTiKVAndTiFlash_en_001_20220428.png)
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TiFlash provides column oriented store and has a coprocessor layer that is efficiently implement with ClickHouse. In addition, it is very similar to TiKV, and relies on the same Raft Region to replicate data in Regions.

TiFlash replicates the data in the TiKV cluster in real time with low consumption and does not block TiKV writes, and at the same time provides consistent read like TiKV, and ensures that the latest data is read. The Region replica in TiFlash corresponds exactly to TiKV, and will be split and merged at the same time as the Leader replica in TiKV.

TiFlash accesses the TiDB cluster as a learner. TiFlash supports table-granular data synchronization. After deployment, no data will be synchronized by default, and the synchronization function needs to be explicitly enabled.