Member-only story
Resolving High CPU Usage in Hibernate-Generated SQL with Index and Data Type Changes
In this post, I will share a performance issue I encountered with Hibernate-generated SQL queries in a Spring Boot application, which led to high CPU usage. Despite adding an index, it didn’t resolve the issue as expected. Only after making certain changes to the database structure, including altering the data types of columns, did I achieve a significant performance boost. I’ll explain why these changes were necessary and how they made a difference.
The Problem: High CPU Usage Despite Indexing
Hibernate, known for simplifying database interaction, generated SQL queries that caused high CPU usage in our application. Typically, when faced with performance bottlenecks, adding an index can help speed up query execution. However, simply adding an index to the affected column did not work in this case.
The Initial Fix: Adding an Index
Our first attempt was to add an index to the column that was being queried frequently. The data type for the column in question was varchar. Normally, adding an index in such a scenario should have improved performance by allowing SQL Server to quickly locate the relevant rows. However, this did not lead to the expected speedup.
