To optimize a SQL database with lots of data, follow these tips:

1. Indexing: Add indexes to columns you search often to speed up data retrieval. Use combined indexes for queries with multiple columns to make them faster.
2. Query Optimization: Write efficient SQL queries. Avoid using SELECT * and choose only the columns you need. Check how queries are running and fix any issues.
3. Database Design: Organize data properly to avoid repetition and errors. Sometimes, adding some repetition (denormalization) can help if your database is mostly read.
4. Partitioning: Split large tables into smaller parts based on things like dates. This helps in managing and querying data more efficiently.
5. Archiving: Move older data to separate tables or databases. This reduces the load on your main tables and speeds up performance.
6. Database Maintenance: Regularly update and clean up your database. Commands like VACUUM in PostgreSQL help keep the database tidy and efficient.
7. Caching: Store frequently used data in memory to avoid repeated database queries, which can speed up access.
8. Hardware and Configuration: Make sure your server has enough resources (CPU, memory, storage) and adjust settings to fit your needs.

Using these methods can greatly improve the performance of a SQL database with large amounts of data.