A computer-implemented method for updating databases that store blockchain data, the method comprising: identifying, based on a transaction associated with a blockchain network, an account identifier of a blockchain account involved in the transaction, wherein the transaction is included in a current block to be appended to a blockchain associated with the blockchain network; appending the current block to the blockchain by performing a consensus algorithm; updating, in a current state object database, an account state corresponding to the account ID of the blockchain account to an updated account state based on the blockchain transaction after the current block is appended to the blockchain, wherein the current state object database is a key-value database that stores key-value pairs of account states mapped to account IDs of blockchain account; wherein the method is characterised in that upon determining a need, updating, in the current state object database, the updated account state based on additional account information of the blockchain account to an second updated account state, wherein the additional account information is loaded from a separate database having a lower storage cost than the current state object database, wherein the additional account information of the blockchain account comprises infrequently accessed account data of the blockchain account; hashing the second updated account state to generate a second hash value of the second updated account state; identifying, in a current state database, a first hash value of the account state corresponding to the blockchain account based on the account ID of the blockchain account, wherein the current state database stores a state tree that is configured to be traversed for current state data, wherein nodes of the state tree store key-value pairs that comprise account IDs and corresponding hash values of the account states of the corresponding blockchain accounts; and updating, in the current state database, the first hash value of the account state to the second hash value of the second updated account state. identifying, based on a transaction associated with a blockchain network, an account identifier of a blockchain account involved in the transaction, wherein the transaction is included in a current block to be appended to a blockchain associated with the blockchain network; appending the current block to the blockchain by performing a consensus algorithm; updating, in a current state object database, an account state corresponding to the account ID of the blockchain account to an updated account state based on the blockchain transaction after the current block is appended to the blockchain, wherein the current state object database is a key-value database that stores key-value pairs of account states mapped to account IDs of blockchain account; wherein the method is characterised in that upon determining a need, updating, in the current state object database, the updated account state based on additional account information of the blockchain account to an second updated account state, wherein the additional account information is loaded from a separate database having a lower storage cost than the current state object database, wherein the additional account information of the blockchain account comprises infrequently accessed account data of the blockchain account; hashing the second updated account state to generate a second hash value of the second updated account state; identifying, in a current state database, a first hash value of the account state corresponding to the blockchain account based on the account ID of the blockchain account, wherein the current state database stores a state tree that is configured to be traversed for current state data, wherein nodes of the state tree store key-value pairs that comprise account IDs and corresponding hash values of the account states of the corresponding blockchain accounts; and updating, in the current state database, the first hash value of the account state to the second hash value of the second updated account state.