Write-Back
In a Write-Back strategy, the application directly writes the data to the cache at first, then after some delay data is written to the database. It ensures recent data is always present in the cache. So the data is easily accessible. This method is suitable for applications with a write-heavy workload. There is possible to risk of data loss if the cache fails before writing to the database. If the cache is not handled properly, it will lead to data inconsistency between the cache and the database. It is also called Write-Behind.
Example: The Write-Back strategy is suitable for the Content Management System (CMS).
The below image shows the Write-Through strategy working mechanism. Consider a content management system that is used for blogging. Authors frequently add or update their blog posts.
- The application first writes the content changes to the cache. Then the cache does write operation to the database with delay (for a predefined period).
- During this delay period, if the author makes further updates to the same blog post, the changes are overwritten by updated content on the cache.
What is Caching Strategies in DBMS?
In today’s digital world, the speed of an application plays a major role in its success. Generally, users expect the applications to run faster with quick responses. Also, It should support seamless experiences across all their digital interactions, whether they’re browsing a website, mobile app, or a software platform. Caching is used to implement a high-speed system with a large number of users. A cache is a high-speed data storage that stores data temporarily to serve future requests faster.
Database caching is like a helper for your primary database (DB). It is a mechanism that stores frequently accessed data in temporary memory. Whenever the application requests the data again, that can quickly get it from this helper, instead of from the main database. Cache helps to reduce the database workloads. So it increases system speed by reducing the need to fetch data from DB.