Performance information for SQL application programming

Efficient applications are an important first step to good system and application performance. As you code applications that access data in Db2, consider performance objectives in your application design.

The following topics can help you understand how application programmers can consider performance as they write applications that access data in Db2 for z/OS®.

Concurrency and programming

The goal is to program and prepare applications in a way that:
  • Protects the integrity of the data that is being read or updated from being changed by other applications.
  • Minimizes the length of time that other access to the data is prevented.
For more information about data concurrency in Db2 and recommendations for improving concurrency in your application programs, see the following topics:

Writing efficient queries

The predicates, subqueries, and other structures in SQL statements affect the access paths that Db2 uses to access the data.

For information about how to write SQL statements that access data efficiently, see the following topics:

Analyzing access paths

By analyzing the access path that Db2 uses to access the data for an SQL statement, you can discover potential problems. You can use this information to modify your statement to perform better.
Tip: Query tuning capabilities that can help you with this task, such as visual explain and statistics advisor, are available in IBM® Db2 Administration Foundation for z/OS and IBM Db2 for z/OS Developer Extension.
For information about how you can use EXPLAIN tables to analyze the access paths for your SQL statements, see the following topics:

Distributed data access performance

The goal is to reduce the amount of network traffic that is required to access the distributed data, and to manage the use of system resources such as distributed database access threads and connections.

For information about improving the performance of applications that access distributed data, see the following topics:

Stored procedures performance

For information about stored procedures and Db2 performance, see the following topics: