Databases & Data Storage

Connection Pooling

Definition

Connection pooling is a technique used to maintain a cache of database connections that can be reused for future requests. Opening a new database connection for every request is an expensive and time-consuming operation.

Why It Matters

Connection pooling dramatically improves the performance and scalability of database-driven applications. By reusing existing connections, it avoids the overhead of establishing new connections for every user request, which is especially important for high-traffic websites.

Contextual Example

A web application creates a pool of 10 database connections when it starts up. When a user request comes in that needs to query the database, the application "borrows" a connection from the pool, uses it, and then "returns" it to the pool so it can be used by the next request.

Common Misunderstandings

  • Improperly configured connection pools can be a source of problems, such as connection exhaustion if the pool is too small.
  • It is a standard feature in most database libraries and application servers.

Related Terms

Last Updated: December 17, 2025