# Hibernate too much memory

**URL:** <https://discourse.hibernate.org/t/hibernate-too-much-memory/537>\
**Category:** Hibernate ORM\
**Created:** [April 12, 2018, 10:07am UTC](https://discourse.hibernate.org/t/hibernate-too-much-memory/537 "2018-04-12T10:07:26Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![ankit\_bansal](https://avatars.discourse-cdn.com/v4/letter/a/fbc32d/32.png) [@ankit\_bansal](https://discourse.hibernate.org/u/ankit_bansal)\
**Post date:** [April 12, 2018, 10:07am UTC](https://discourse.hibernate.org/t/hibernate-too-much-memory/537/1 "2018-04-12T10:07:26Z")

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Hi,

I am using hibernate with spring boot.  
I am firing one query which joins 3 tables and stores data in projection(only 5 columns) and fetch 300 rows(so 300 objects).

But this takes lot of memory, I am debugging it and found there are too many instances of

**java.util.concurrent.ConcurrentHashMap**  
Count : 854  
Retained Size : 20MB

**Others**

java.util.concurrent.ConcurrentHashMap$Node[]  
java.util.concurrent.ConcurrentHashMap$Node

What is this size for?  
Can it be reduced? Its contans Map inside map inside map ?

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<div class="post-metadata">

**Author:** ![vlad](https://yyz1.discourse-cdn.com/flex035/user_avatar/discourse.hibernate.org/vlad/32/658_2.png) [@vlad](https://discourse.hibernate.org/u/vlad)\
**Post date:** [April 12, 2018, 10:24am UTC](https://discourse.hibernate.org/t/hibernate-too-much-memory/537/2 "2018-04-12T10:24:34Z")

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Show us a profile report. Otherwise, how would we know whether this is Hibernate and not some other framework you use.

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<div class="post-metadata">

**Author:** ![ankit\_bansal](https://avatars.discourse-cdn.com/v4/letter/a/fbc32d/32.png) [@ankit\_bansal](https://discourse.hibernate.org/u/ankit_bansal)\
**Post date:** [April 12, 2018, 10:39am UTC](https://discourse.hibernate.org/t/hibernate-too-much-memory/537/3 "2018-04-12T10:39:35Z")

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![Screenshot%20from%202018-04-12%2016-03-39](https://cdck-file-uploads-canada1.s3.dualstack.ca-central-1.amazonaws.com/flex035/uploads/hibernate/original/1X/0b558166f1c285a677917364f1d97212ec4c11e8.png)

I have uploaded two snapshot of dumps

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<div class="post-metadata">

**Author:** ![ankit\_bansal](https://avatars.discourse-cdn.com/v4/letter/a/fbc32d/32.png) [@ankit\_bansal](https://discourse.hibernate.org/u/ankit_bansal)\
**Post date:** [April 12, 2018, 10:40am UTC](https://discourse.hibernate.org/t/hibernate-too-much-memory/537/4 "2018-04-12T10:40:09Z")

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![Screenshot%20from%202018-04-12%2016-08-32](https://cdck-file-uploads-canada1.s3.dualstack.ca-central-1.amazonaws.com/flex035/uploads/hibernate/original/1X/82b1f59781170394b2f60f1c3ec46d0a2f0c87a3.png)

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<div class="post-metadata">

**Author:** ![vlad](https://yyz1.discourse-cdn.com/flex035/user_avatar/discourse.hibernate.org/vlad/32/658_2.png) [@vlad](https://discourse.hibernate.org/u/vlad)\
**Post date:** [April 12, 2018, 10:57am UTC](https://discourse.hibernate.org/t/hibernate-too-much-memory/537/5 "2018-04-12T10:57:00Z")

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[org.springframework.beans.CachedIntrospectionResults](https://docs.spring.io/spring-framework/docs/current/javadoc-api/org/springframework/beans/CachedIntrospectionResults.html) is surely not a Hibernate class.

You should ask the Spring guys why does it consume so much memory.