Supabase is like an open-source version of Firebase. It offers a bunch of tools and services, such as real-time databases, authentication, and storage. It's all built on PostgreSQL, which is a pretty solid open-source relational database system.

Now, database replication in PostgreSQL is a neat trick to boost your database's availability. It creates one or more copies of your database, called replicas. With read replicas, the data from your main database server gets copied to a secondary server. These read replicas help spread the read load across multiple nodes, making your system more scalable.

First things first, you need to create read replicas for your Supabase database. If you're using AWS RDS for PostgreSQL, it's a breeze. Just log in to the AWS Management Console, pick the instance you want to replicate, and head over to the 'Actions' tab. Then, select 'Create read replica'. You'll have to set up the replica settings, like how many instances you want.

Connection pooling is super important for making the most out of your database connections. In Supabase, connection pooling is handled by PgBouncer, a PostgreSQL connection pooler. You'll need to set up PgBouncer to act as a load balancer, distributing database connections evenly to your read replicas.

Once your read replicas and connection pooling are set up, the next step is to make sure all read queries go to the replicas. You can do this by tweaking your application's database connection string to point to the pooler instead of the database.

Read queries are basically ‘SELECT’ statements used to fetch data from the database. You'll need to update your application code to direct all these read queries to the read replicas.

After you've got your read queries going to the read replicas, keep a close eye on your database system's performance. If you spot any issues, you might need to adjust the number of read replicas or change how the load is distributed among the nodes. It's crucial to make sure read queries are spread evenly across all replicas for maximum scalability.

Also, use Supabase monitoring tools to keep track of your database performance. Regular monitoring helps you catch any performance hiccups early and fix them quickly, ensuring smooth and efficient data operations.

Remember, handling database scalability with read replicas requires a good grasp of how databases work, an understanding of your application's specific database load, and the ability to tweak the configuration based on your replication setup's performance. If you're ever unsure, check out Supabase’s official documentation.