# RocksDB Column Family
+ Lock cf
+ Write cf
+ Default cf
+ Multiple cfs share a WAL file.
+ Each cf has a separate memtable, block-cache and many SST files.

sst
+ disk
memtable
+ memory
block-cache
sst
sst
sst
sst
sst
sst
+ disk
memtable
+ memory
block-cache
sst
sst
sst
sst
sst
sst
+ disk
memtable
+ memory
block-cache
sst
sst
sst
sst
sst
WAL (disk)
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