- The document discusses techniques for efficient and thread-safe database access from web servers including using synchronized blocks, prepared statements, and connection pooling. - Synchronized blocks allow only one thread to execute a block of code at a time to prevent race conditions when multiple threads access a shared resource like a database. - Prepared statements improve efficiency by parsing SQL statements once instead of each time they are executed, allowing values to be bound dynamically. - Connection pooling reuses existing database connections instead of creating new ones for each request, improving performance.

1. Server-side Web Programming Lecture 14: Efficient and Safe Database Access on Web Servers

4. Synchronized Database Access Get quantity Quantity = 100 Client 1 thread Get quantity Quantity = 100 Client 2 thread Set quantity = 99 Store 99 in database Set quantity = 99 Store 99 in database Problem: this code should not be interrupted!

6. Synchronized Database Access