Should be aware of the storage hierarchy

1. Database is usually data-intensive
2. cache miss is important

Pay attention to the hardware properties

1. Sequential access and random access is usually different
2. bandwith and IOPS

Design Issues

1. choose a proper index
2. support variable length data
3. for most secondary storage, try avoid random writes
4. reduce the write amplication
5. group your writes

Optimization On LSM-tree

1. optimize write amplication
2. optimize read performance
3. other optimizations: cache, special workload