What is PgBouncer and why do you need it?

PgBouncer is a lightweight connection pooler for PostgreSQL. It acts as a middleman between the application and the database.

When an application opens a new connection to PostgreSQL, it costs significant resources: process initialization, authorization, memory allocation. With a large number of clients, this becomes a bottleneck.

#How PgBouncer solves this

1. It keeps a limited number of active connections to PostgreSQL.
2. When the application requests a connection, PgBouncer hands out one of the existing ones instead of creating a new one.
3. After the query finishes, the connection goes back into the pool and can be reused.

#Advantages

• significantly reduces load on the database server;
• speeds up application response time with many clients;
• lets you manage connection limits and timeout policy centrally;
• improves resilience, brief PostgreSQL outages can be recovered from without restarting applications.

In short, PgBouncer is a "buffer" that makes working with PostgreSQL faster, more stable, and more resource-efficient.