[hibernate-users] Newbie Performance Questions

[Eric Kolotyluk]

I have been using Hibernate since January 2011, but more recently I am 
integrating things into some UI. For some context I have an application 
that deals with libraries of colors.

Our current application stores the libraries in XML files under Castor 
on the local file system. A given library has 2,000 colors in it and 
takes maybe 200 ms to load.

My JPA framework looks something like

@Entity Library - m2m - @Entity Color - m2m - @Entity Representation 
(i.e. L*a*b*)

In my application, loading from a PostgreSQL database via Hibernate the 
same data takes

 1. 20 seconds to load with full logging enabled
 2. 16 seconds to load with logging disabled
 3. 4 seconds to reload a second time (probably due the default caching
    behavior)
 4. 0.2 seconds from via SQL from PostgreSQL
 5. 0.2 seconds to load from Castor
 6. 0 seconds (usually) if I use SoftReferences to cache the data in memory

Some of my questions are:

 1. Is the performance I am seeing typical? Is it what most people would
    agree to expect from using Hibernate with a DBMS like PostgreSQL?
 2. When logging is turned on, I see what looks like an obscene amount
    of SQL produced for only 2,000 colors. When logging is turned off,
    16 seconds still seems like an awfully long time to load 2,000 color
    representations, where running an SQL query to extract the same data
    takes 203 ms.
 3. What exactly is taking so long? Using Hibernate I basically load the
    library object, then iterate over all the colors it has, then for
    each color object I get the representation object and load the
    L*a*b* data into the UI.
 4. Am I making some lame newbie mistake somewhere, and what would that
    mistake be?
 5. Should I be formulating an appropriate HQL statement, similar to my
    SQL statement, and loading things that way?
 6. Is there some documentation on using Hibernate with Graphical User
    Interfaces, or some best practices documentation somewhere?

Cheers, Eric
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