What is database performance tuning?

• Database Performance Tuning Definition

  Database Performance Tuning Definition

  Database performance tuning refers to a group of activities DBAs perform to ensure databases operate smoothly and efficiently. It helps re-optimize a database system from top to bottom, from software to hardware, to improve overall performance.

  Tuning involves accelerating query response, improving indexing, deploying clusters, and reconfiguring OSes according to how they're best used to support system function and end-user experience. MySQL and Oracle are prominent examples of database management systems (DBMS) on which DBAs generally perform database tuning.
• What Is Involved in Database Performance Tuning

  What Is Involved in Database Performance Tuning

  Poor indexing, improper queries, and memory constraints are common reasons for inefficient and slow database performance. Database performance tuning plays an essential role in optimizing the complete database system to ensure high availability and quick response times. Outlined below are some of the best practices for effective performance tuning:

  • Execution plans in MySQL help the database professionals identify poorly performing queries. To carry out performance tuning in the most efficient way, look at the 'actual execution plan' for the most accurate information and additional details about query execution.
  • Update the database to the latest version. Newer database versions perform better than older ones, boosting overall database effectiveness.
  • Data defragmentation is a great way to troubleshoot slow and underperforming databases. It involves grouping together relevant data, making it easier and faster for queries to access the needed information and speeds up I/O operations.
  • Collect baseline metrics (e.g., query response times, peak and off-peak operation hours, etc.) and compare them with the current database performance to spot issues.
  • Increase memory allocation across computing systems to ensure there's sufficient memory available for the database. Similarly, upgrading the CPU can help mitigate database slowdowns when juggling different requests.
  • Review inefficiencies across queries as poorly written queries account for most database performance issues. When tuning queries, consider starting with expensive operations and then moving on to the others.
  • Improving indexes is vital for optimal database performance tuning. Use 'covering index' to put all the required query fields in the index and avoid additional data lookups in the table, speeding up data retrieval operations. Also, avoid common indexing errors such as correlated subqueries and coding loops.
  • Consider using a database performance analysis tool utilizing response time analysis to quickly and efficiently track, detect, and troubleshoot database problems. Performance analysis tools improve operational efficiency by automating the time-intensive and error-prone manual tuning process.
• SQL Query Performance

  SQL Query Performance

  Gauging SQL query performance is critical to improving a database's overall effectiveness and performance. It’s measured by analyzing query response time and throughput, i.e., the number of queries completed within a specific time. A minor lag in response times can quickly result in a significant performance slowdown which could take a long time to resolve.

  SQL query performance tuning uses different techniques and procedures to reduce query response time and overall resource utilization. Generating an optimized execution plan, keeping track of resource consumption, reviewing index table alignment, and analyzing SQL statements are common ways to better SQL query performance.
• Oracle Query Performance

  Oracle Query Performance

  Oracle is a popular DBMS where query performance optimization is vital in ensuring high database efficiency. There are several ways to optimize queries in Oracle. Collecting statistics on base tables enables 'Oracle Text' to choose the most efficient query execution plan. Partitioning data and designing local partitioned indexes also enhances query performance. Similarly, the Oracle Text ‘tracing facility’ helps database professionals identify issues with indexing and querying. Other ways to performance tune queries in Oracle include using inner joins over outer joins, indexing predicates, and rewriting subqueries with Global Temporary Tables (GTT).

  An automated database performance analysis tool using wait-time analytics is also a great way to optimize queries and indexes for Oracle database performance tuning. It helps save time spent on manual tuning, automates indexing, identifies queries to focus on, and provides recommendations on efficiently adjusting poorly written queries. These tools also help search SQL queries based on the application name, user, host, and certain parts of SQL statements like table or column names. This further helps resolve the issue based on wait time details, executions, and other performance metrics. Apart from query optimization, these tools provide an overview of database activity, wait times, SQL statements, and other critical metrics to highlight the exact cause of issues encountered.