IndexDB different
RDBMS?
Answers
Answer:
IndexedDB is a way for you to persistently store data inside a user's browser. Because it lets you create web applications with rich query abilities regardless of network availability, these applications can work both online and offline. IndexedDB is useful for applications that store a large amount of data (for example, a catalog of DVDs in a lending library) and applications that don't need persistent internet connectivity to work (for example, mail clients, to-do lists, and notepads).
About this document
This introduction discusses essential concepts and terminology in IndexedDB. It gives you the big picture and explains key concepts.
You'll find the following useful:
For an overview of the design and structure of IndexedDB, see Big Concepts.
To learn more about IndexedDB terms, see the Definitions section.
For a detailed tutorial on how to use the API, see Using IndexedDB.
For the reference documentation on the IndexedDB API, refer back to the main IndexedDB API article and its subpages, which document the types of objects used by IndexedDB.
For more information on how the browser handles storing your data in the background, read Browser storage limits and eviction criteria.
Overview of IndexedDB
IndexedDB lets you store and retrieve objects that are indexed with a "key." All changes that you make to the database happen within transactions. Like most web storage solutions, IndexedDB follows a same-origin policy. So while you can access stored data within a domain, you cannot access data across different domains.
IndexedDB is an asynchronous API that can be used in most contexts, including Web Workers. It used to include a synchronous version also, for use in web workers, but this was removed from the spec due to lack of interest by the web community.
IndexedDB used to have a competing spec, WebSQL Database, but the W3C deprecated it on November 18, 2010. While both IndexedDB and WebSQL are solutions for storage, they do not offer the same functionalities. WebSQL Database is a relational database access system, whereas IndexedDB is an indexed table system.
Big concepts
If you have assumptions from working with other types of databases, you might get thrown off when working with IndexedDB. So keep the following important concepts in mind:
IndexedDB databases store key-value pairs. The values can be complex structured objects, and keys can be properties of those objects. You can create indexes that use any property of the objects for quick searching, as well as sorted enumeration. Keys can be binary objects.