Managing Oracle Database's performance requires careful attention to various details that complicate efforts to tune the software, monitor query throughput and respond to performance problems. It's a tall order but crucial to efficient processing operations in Oracle environments.
Database administrators (DBAs) must ensure that supported applications can access data as efficiently as possible without compromising the user experience or database operations. Any bottlenecks that degrade performance must be identified and eliminated quickly so they have minimal impact on transaction processing or data warehousing workflows.
To that end, here are six best practices on Oracle performance monitoring and tuning that DBAs should adopt to help keep their database systems running smoothly.
1. Be proactive on performance management
DBAs should take a proactive approach on performance management to ensure the ongoing efficiency and stability of the Oracle Database environment. Being proactive helps DBAs prepare for performance issues that arise so they can quickly detect, understand and address the problems. Even on issues that call for immediate action, proactive DBAs will be ready to react to them.
A proactive strategy might, for example, include establishing performance baselines that DBAs can reference as they monitor and manage Oracle systems. Baselines provide statistics about the performance of databases, applications, the OS, networks and disk I/O -- information that can be used to identify current or potential issues.
DBAs should also have clear performance objectives for the systems they manage and understand the processing outcomes they're trying to achieve. Regularly monitoring database servers and storage platforms against those objectives is essential to carry out performance assessments, identify potential issues and troubleshoot known problems.
2. Think outside the database box
A wide range of factors outside of Oracle Database can affect its performance. Fast application throughput relies not only on the database management system (DBMS) being highly optimized, but also on ensuring that the host IT infrastructure properly supports it. As a result, thorough knowledge of the overall environment is essential when evaluating performance issues. For example, Oracle performance might slow down because nondatabase tasks running on the same server start to consume more CPU resources.
The storage platform is also an important consideration on Oracle performance monitoring and management. The types of drives that are used influence performance and so do aspects like storage protocols, disaster recovery setups and the use of server-side caching. Network hardware and software components are critical considerations as well.
Because of the possible performance implications, organizations should be wary of implementing Oracle Database on a shared platform. Consolidating multiple workloads on a single server can alter database performance in unexpected ways and make troubleshooting issues more difficult. In most cases, the DBMS should be deployed on a dedicated platform. Although that approach is costlier, the benefits likely will be well worth the investment.
3. Think inside the database box
Oracle Database is, of course, at the center of the Oracle application universe and should be the DBA's top concern on performance management. A good place to start is to consider the many optional features available with the database software, such as the partitioning, advanced compression and Oracle Database In-Memory options. Although such features come with additional licensing fees, they might be warranted in order to deliver the necessary performance.
DBAs should also pay close attention to the server and database configuration settings that control the DBMS. The full database caching mode setting, for example, makes it possible to cache an entire database in memory to boost performance. Additionally, DBAs should ensure that database files and buffer caches are sized properly to support the intended workloads.
Another important step is to evaluate how database design affects performance. Although changing the design of a database can be a sizeable effort after it's in production, a poorly designed database will likely have long-term consequences that will only get worse.
4. Make SQL queries sing
Poorly written SQL statements play a big role in slow database performance. In fact, SQL statements that don't run efficiently represent a significant portion of all Oracle performance problems. For this reason, Oracle performance monitoring and management efforts should carefully assess and tune each SQL query to ensure that it uses the most efficient execution plan available and has the least possible impact on performance.
The SQL optimization process should also include a careful evaluation of how databases are indexed. If properly implemented, indexes can greatly improve SQL query performance. But an inadequate index design can have the opposite effect. It isn't just a one-time check, either: An effective indexing strategy is an ongoing process wherein the existing indexes should be monitored and modified as workloads evolve.
5. Choose the right performance management tools
As part of its Oracle Enterprise Manager software, Oracle provides a wide range of tools to help DBAs manage database performance. For example, the Automatic Workload Repository (AWR) stores performance-related statistics, while the Automatic Database Diagnostic Monitor can be used to analyze AWR data.
Oracle also offers such tools as Active Session History for diagnosing data about active user sessions, SQL Tuning Advisor to help optimize SQL statements and SQL Access Advisor for recommendations on how to implement indexes and materialized views showing query results.
In addition, DBAs can turn to numerous third-party technologies to help address performance issues. That gives organizations a multitude of performance management tools from which to choose; DBAs will likely need a variety of them to effectively monitor and manage Oracle Database performance.
6. Consider the entire data workflow
When addressing Oracle Database performance issues, DBAs should consider the entire workflow, from the tables in the database to the users accessing data within those tables. Keeping the user's perspective at the forefront is critical to effective database performance management. Users are the most important part of the workflow, and their feedback -- coupled with knowledge of what they're doing in databases -- is essential to maintaining optimal performance.
That said, Oracle performance monitoring and management should also take into account all of the databases, database instances, applications and other workflow components, including any abstraction layers that might have a detrimental effect on performance. Scalability issues must also be factored into the equation. The goal is to identify the real issues before attempting to address performance problems, which requires a full understanding of the application stack that's built on top of Oracle Database.