Hibernate Tips: Count the executed queries in a Session

Take your skills to the next level!

The Persistence Hub is the place to be for every Java developer. It gives you access to all my premium video courses, monthly Java Persistence News, monthly coding problems, and regular expert sessions.

Hibernate Tips is a series of posts in which I describe a quick and easy solution for common Hibernate questions. If you have a question you like me to answer, please leave a comment below.


Some of my use cases are slow and seem to perform too many queries. How can I count all queries executed within a Hibernate Session?


The easiest way to count all executed queries is to activate Hibernate’s statistics component. Hibernate then collects a lot of internal statistics and provides them as a log message and via the Statistics API. Collecting all these information takes some time, so do not use this in production!

Hibernate’s statistics component is deactivated by default. You can activate it by setting the hibernate.generate_statistics parameter to true. You can either do this by providing a system property with the same name or by setting the parameter in the persistence.xml file.

  <persistence-unit name=”my-persistence-unit”>
    <description>Hibernate Tips</description>

      <property name=”hibernate.generate_statistics” value=”true” />

You have 2 options to access the statistics. Hibernate can write a subset with the most important information of each session to the log file or you can access them via the Statistics API. Let’s have a look at the log messages first. Hibernate writes a log message, similar the following one, at the end of each session. You can find the number of SQL statements and the time spent for their preparation and execution in line 4 and 5.

16:24:55,318 INFO [org.hibernate.engine.internal.StatisticalLoggingSessionEventListener] – Session Metrics {
25659 nanoseconds spent acquiring 1 JDBC connections;
22394 nanoseconds spent releasing 1 JDBC connections;
1091216 nanoseconds spent preparing 12 JDBC statements;
11118842 nanoseconds spent executing 12 JDBC statements;
0 nanoseconds spent executing 0 JDBC batches;
0 nanoseconds spent performing 0 L2C puts;
0 nanoseconds spent performing 0 L2C hits;
0 nanoseconds spent performing 0 L2C misses;
16999942 nanoseconds spent executing 1 flushes (flushing a total of 17 entities and 17 collections);
63915 nanoseconds spent executing 1 partial-flushes (flushing a total of 0 entities and 0 collections)

You can access the Statistics API via Hibernate’s SessionFactory. It provides a lot more information than the log output.

Statistics stats = sessionFactory.getStatistics();
long queryCount = stats.getQueryExecutionCount();

Learn more:

If you want to learn more about finding and fixing Hibernate performance issue, you should have a look at the following posts:

Hibernate Tips Book

Get more recipes like this one in my new book Hibernate Tips: More than 70 solutions to common Hibernate problems.

It gives you more than 70 ready-to-use recipes for topics like basic and advanced mappings, logging, Java 8 support, caching, and statically and dynamically defined queries.

Get it now!