[Retracted] SmartMedChain: A Blockchain-Based Privacy-Preserving Smart Healthcare Framework

Table 1

Comparison between Blockchain Database Storage solutions.

Ref	Database solution	Scalability	Storage-caused performance	Data formatting	Query processing
[10]	LevelDB	Y	Y	N	N
[11]	Relational database	N	Y	Y	N
[12]	MongoDB	N	Y	Y	N
[13]	Distributed hash table	N	Y	Y	Y
[9]	Distributed database	N	Y	Y	Y
[14]	Key-value file systems	N	Y	N	N