What are database connection pools and how do they help with scaling?

A connection pool is a cache of database connections that are maintained so that

connections can be reused when future requests to the database are made. Instead of

opening and closing a new connection each time a query is executed, the application can

reuse existing connections from the pool.

• How it helps with scaling:
• Improves efficiency: Reusing connections reduces the overhead of

establishing new connections, leading to faster query execution.

• Reduces resource consumption: By limiting the number of connections to

the database, the pool avoids overloading the database with too many open

connections.

• Improves scalability: Connection pools help handle a large number of

requests without overwhelming the database. The pool can be scaled by

adjusting the maximum number of connections based on the workload.

Example: A connection pool size can be set to 100, meaning up to 100 connections to the

database can be active at once, with others waiting in line for an available connection.