Category: Blockchain

Oracle blockchain tables

Today, I came across one of my friends who was having the misconception of oracles in Blockchain as part of Oracle database. So, I thought of writing this small article to explain what exactly oracles in Blockchain are and how they are different from inbuilt blockchain tables in oracle database.
When we talk about oracles in Blockchain technology it means that oracles in blockchain are entities who connect blockchain with external system and as per the inputs and outputs smart contracts are executed. Smart contracts are deployed on blockchain, and they execute transactions which are transparent and irreversible.

Blockchain Tables in Oracle

When we talk about blockchain tables in oracle they are the tables where we can only append the data, or we can say we can only insert the data. We can also restrict the deletion of rows either by specifying the value as shown in the below example:
SQL> CREATE BLOCKCHAIN TABLE Tryblockchain (test1 VARCHAR2(128), t NUMBER)
    NO DROP UNTIL 1 DAYS IDLE
    NO DELETE UNTIL 16 DAYS AFTER INSERT
    HASHING USING “SHA2_512” VERSION “v1”;  
Table created.

Now, in the above create table command a blockchain table will be created with parameters “No Drop until 1 days idle” means that table can be dropped after one day of no insertion of rows in the table and if we want that table not to be dropped forever we will define “No drop”. Other parameter “No delete until 16 days after insert” means that each row in the table is protected from deletion as per the specified number of days and minimum value is 16. Next parameter “Hashing Using ‘SHA2 512’” specifies the encryption, chaining up rows, validate the data and making it temper resistant.
Oracle blockchain table helps in implementing the centralized ledger model where all the users have the access to the temper proof ledger.
Blockchain tables helps in creating a centralized ledger model by reducing the overhead costs of the project, saves time in comparison to the decentralised system.
Apart from the above features while creating centralized ledger system it is easier to maintain in house like taking the backup, archiving, providing the controlled access, faster access of data and output to the end user and no additional infrastructure is required except the already installed Oracle database. 

Blockchain is a shared, peer to peer, immutable distributed

Blockchain is a shared, peer to peer, immutable distributed ledger in which all the transactions are cryptographically secure. Blockchain provides users a decentralized public network which is not controlled by a single user or entity. It makes the system robust and secure against any sort of tempering with the data. Block chain helps peer to peer transactions without any intervention of the third party. Blockchain consists of more than one block and each block can be also referred to a node and each transaction is validated by each node. The very first block is known as Genesis block followed by n number of blocks. A single block consists of data and hash value (Unique Signature) which is depicted in the below diagram.