Why Do I Hate Hibernate?

Why Do I Hate Hibernate?
Mikalai Alimenkou
http://xpinjection.com
13.09.2011

Nobody understand how equals and hashCode must look like
There is no common solution
It is hard decision when there is no “unique business key” for the entity
Many issues with inclusion of child collections in calculation

Mutable objects are evil
Default constructor must present
Fields can’t be final
State of object may become inconsistent
Or… reflection magic will happen

DTO is evil pattern with Hibernate
Lots of code duplication
Hard to maintain if many entities exists
No simple and common pattern implementation
Silent DTO mapping errors
With large object tree it is like hell

Criteria API or HQL?
Some simple things are missed in Criteria API (for example, filtering by collection of elements)
Mixing HQL and Criteria API looks strange
Criteria API is designed for dynamic queries, but not HQL

To update single field you should read full entity
Child collections retrieved as well or made lazy
Few people understand in details how lazy loading works
At least 2 SQL queries to update single field
This pattern makes developers stupid

Parent records are copied to temporary table on update or delete

Entity state can be managed only from one side in parent-child relationship

Flush on commit is too unpredictable
Entity can’t be changed to avoid DB update
Child collections must be copied before modification
Constraint exception handling code may be missed at all
No control of queries ordering that may cause deadlocks

Documentation is simple but primitive
Only basic samples are covered
For all complex things you need to consult with books (“Java Persistence with Hibernate” is the best)
Bug reports are ignored by development team

Hibernate makes developers stupid
Many of them don’t know JDBC at all
Few people go deeper than simple mapping
Almost nobody count number of SQL queries performed and their structure
Very few people know how to tune Hibernate via JDBC parameters

Any questions?

Why Do I Hate Hibernate?

by Mikalai Alimenkou on Sep 14, 2011

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Why Do I Hate Hibernate? — Presentation Transcript