# KV Pair Storage in RocksDB (2/2)

+ Lock cf

+ key -> start_ts/PUT/value

+ key+commit_ts -> start_ts/PUT/value
+ Write cf
+ Default cf
+ The row key is about 20 bytes; the index key is from 30 bytes to several hundred bytes.
+ If the value is very short, writing multiple cfs causes increased storage space and write overheads.
+ If value <= 64 bytes, the value is in the lock cf in the preparation phase; the value is written in the write cf in the commit phase.

Where is the index stored？
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