Setting up AWS RDS PostgreSQL Logs for Performance Tuning

In my last article “9 Step Performance Tuning AWS RDS PostgreSQL I left out an important part. I mentioned using the PostgreSQL logs to identify queries that are taking a long time to execute. But I did not say how.

You can use the following steps to identify slow queries using PostgreSQL logs:

1. Enable logging: Make sure that logging is enabled in the PostgreSQL configuration. You can enable it by setting the logging_collector parameter to on and specifying the log_directory and log_filename parameters.
2. Configure logging level: Set the log_min_duration_statement parameter to a value that is appropriate for your application. This parameter specifies the minimum duration of a statement in milliseconds that will be logged.
3. Analyze logs: After enabling logging, you can analyze the logs to identify slow queries. The logs can be found in the directory specified by the log_directory parameter.
4. Look for slow queries: Look for statements that have a duration greater than the value specified in the log_min_duration_statement parameter. These statements may indicate queries that are taking a long time to execute.
5. Identify query details: Once you have identified a slow query, look at the details of the query, such as the query plan and the indexes used. This information can help you optimize the query.
6. Analyze query performance: Use the EXPLAIN command to analyze the query plan and identify any performance bottlenecks. You can also use tools such as pg_stat_statements to collect statistics on query performance.

By following these steps, you can use PostgreSQL logs to identify queries that are taking a long time to execute and optimize them for better performance.