What is a Subgraph in Blockchain :
A long time ago, the world was introduced to a technology that will forever change its perspective on centralized systems and currencies. In 2008, Satoshi Nakamoto authored a paper titled, ‘Bitcoin: A Peer-to-Peer Electronic Cash System to the public. This paper introduced a decentralized platform with a proof-of-work consensus mechanism for data validation and mining. This technology proposed by the report was launched in 2009 and would house the first cryptocurrency blockchain.
Blockchain functions through subgraphs which collects data from the blockchain and processes it. Subgraphs are also known as Application Programming Interface, and their importance in the workings of blockchains cannot be underestimated. The subsequent section examines the concept of subgraphs and why they should be regarded as essential.
What are Subgraphs
Subgraphs are data structures that organize all data from a blockchain or a blockchain-related platform. In simpler terms, subgraphs enable developers to pull data from the blockchain and decide how to index and store data. These data can range from calculations, pre-aggregations or other forms of information. Subgraphs present an Application Programming Interface that gathers data or can be used for query or information search. A developer can develop a subgraph using the graph-node command-line instrument or the graph docker image. Subgraphs have three components such as a manifest, a schema, and mappings.
A Subgraph manifest is a platform that has information on the details and components of the subgraph. These will include data sources, templates, and other features. It is the information center of the subgraph that contains information data sources and templates. It also analyzes the dApps needs and provides information about such conditions. A manifest is permanently attached to every subgraph as it shows the subgraph’s requirements and other data about the subgraph.
Secondly, a schema is a component of the subgraph that determines how data obtained by manifest is stored and how to query it. Schemas define data models and entities that have been indexed. Schemas are generally called GraphQL schemas because they use GraphQL interface definition language.
Finally, Mappings are written in AssemblyScript code, which aids in locating an event or information in the manifest. AssemblyScripts are a sub-set of TypeScript, only stricter with a more familiar syntax. They define the event handlers that transform the data and save it on the Graph Node store.
All subgraphs are essential components of graphs, allowing a developer to build and deploy an Application Programming Interface with indexed data from decentralized networks on blockchain and how they should be stored. The manifest is a file on the subgraph for a more precise grasp of the concept. This manifest will house the Schema that defines the file and the mappings. The Schema, however, would determine how data and information are stored in the system. Finally, the mappings would aid the location and extraction of the data gleaned from the Schema.