# `TiKV MVCC`

| Column Family | Key             | Value                      |
| :------------ | :-------------- | :------------------------- |
| `Default`     | `key,start_ts`  | `value`                    |
| `Lock`        | `key`           | `start_ts,primary_key,ttl` |
| `Write`       | `key,commit_ts` | `start_ts[,short_value]`   |

+ **`start_ts:`** Timestamp when the transaction begins
+ **`commit_ts:`** Timestamp got after prewrite, used in commit
+ **`primary_key:`** `Key` used to store the status of transaction 
+ **`short_value:`** Value which is of short type (with length <64 bytes)

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