What are the best techniques for reducing database latency?

2 Optimize your schema and indexes

Designing your database schema and indexes can have a major effect on latency. A well-structured schema can reduce the data that needs to be scanned, transferred, and processed by the database server, while a well-crafted index can speed up query execution. To optimize your schema and indexes, use appropriate data types and sizes for your columns, normalize your data to avoid redundancy and inconsistency, use foreign keys and constraints to ensure data integrity and relationships, create indexes on columns used in queries, filters, and joins, avoid over-indexing or under-indexing that can decrease performance, use composite indexes to combine multiple columns into one index, and use partial indexes to index only a subset of data that meets a condition.

3 Tune your queries and parameters

Writing and executing queries and parameters correctly are key to reducing latency. Poorly written or executed queries can cause unnecessary load on the database server, whereas well-written and executed queries can reduce the amount of data that needs to be retrieved, sorted, and aggregated. To get the best performance out of your queries and parameters, you should use prepared statements and bind variables to avoid SQL injection and parsing overhead. Additionally, query analyzers and explain plans can help you identify and fix performance bottlenecks. Limit and offset clauses are useful for paginating large result sets, while order by and group by clauses can help sort and aggregate data on the database server. Joins and subqueries are also great for combining data from multiple tables. Furthermore, it's important to avoid full table scans and nested loops that can slow down query execution. Finally, caching and materialized views, as well as partitioning and sharding, can be used to store frequently accessed or computed data in smaller, more manageable chunks.

4 Monitor and benchmark your database performance

Monitoring and benchmarking your database performance is the final technique for reducing database latency. Doing this allows you to identify and diagnose latency issues, as well as measure and compare the effectiveness of your optimization techniques. To achieve this, you should use database monitoring tools and metrics to track and visualize latency and other performance indicators. Database logging and auditing can record and analyze query activity and errors, while database profiling and tracing can capture and examine query execution plans and statistics. Additionally, you should use database testing and load testing to simulate and evaluate different scenarios and workloads, as well as database tuning and optimization tools to suggest and apply performance improvements.