I. Introduction
The underlying data of the blockchain can be divided into state data and ledger data. The state data can be updated, deleted, and other operations. In contrast, the ledger data is accumulated and recorded in the order of time, which can only be written in append mode, and cannot be modified or deleted. Therefore, the year by year increase in storage overhead and the query of data on the chain have gradually become prominent, and these problems are closely related to the data storage system at the bottom of the blockchain [1].