An in-memory database is a type of database that stores data in the computer's main memory or RAM, giving it faster access speed compared to other types of databases. This makes it particularly useful for applications that require very high or real-time read/write speeds such as gaming, web applications and financial transactions. In contrast to traditional databases which store their data on disk, in-memory databases are generally limited in the amount of data they can store due to their reliance on the computer's available RAM. ## In-Memory Database Advantages - Data is accessible almost instantly ## In-Memory Database Disadvantages - Storing data in-memory is more expensive than on disk - In the event of a database failure, data loss will occur ## In-Memory Database Use Cases - Cache - Ecommerce - Gaming - Leaderboard - Session management - Social chat or news feed - Personalization - Adtech ## Popular In-Memory Databases - Redis - Memcached %% wiki footer: Please don't edit anything below this line %% ## This note in GitHub <span class="git-footer">[Edit In GitHub](https://github.dev/data-engineering-community/data-engineering-wiki/blob/main/Concepts/In-Memory%20Database.md "git-hub-edit-note") | [Copy this note](https://raw.githubusercontent.com/data-engineering-community/data-engineering-wiki/main/Concepts/In-Memory%20Database.md "git-hub-copy-note")</span> <span class="git-footer">Was this page helpful? [👍](https://tally.so/r/mOaxjk?rating=Yes&url=https://dataengineering.wiki/Concepts/In-Memory%20Database) or [👎](https://tally.so/r/mOaxjk?rating=No&url=https://dataengineering.wiki/Concepts/In-Memory%20Database)</span>