[Hibernate-issues] [Hibernate-JIRA] Commented: (HB-12) low performance loading with optional 1-1 association

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The following comment has been added to this issue:

     Author: Gavin King
    Created: Sun, 9 Nov 2003 12:27 AM
       Body:
fixed (finally) for load(), get() and Criteria queries .... other cases to come: HQL queries, collection initialization.
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View the issue:

  http://opensource.atlassian.com/projects/hibernate/secure/ViewIssue.jspa?key=HB-12


Here is an overview of the issue:
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        Key: HB-12
    Summary:  low performance loading with optional 1-1 association
       Type: Bug

     Status: Assigned
   Priority: Major

    Project: Hibernate2

   Assignee: Gavin King
   Reporter: Max Rydahl Andersen

    Created: Sat, 3 May 2003 10:02 AM
    Updated: Sat, 3 May 2003 10:02 AM

Description:
low performance loading with optional 1-1 association
I use Hibernate 1.2.3. 

There is a problem, which causes a severe performance loss: 

If you have 2 entites (A and B) with a 1-1 association, 
Hibernate uses an SQL query with a join (if enabled) to 
load both entites with 1 statement. Wonderful! If there 
is a B for an A, everything is okay. 

If there is no B for a certain A, Hibernate tries 
(although the 1st statment returned no instance for B) 
to load B, when you invoke the corresponding getter, 
which results in an unnecessary SQL query! 

If there are many entities associated, there are many 
unnecessesary SQL queries and the performance suffers. 

Thanks 
Markus 

(Original: http://sourceforge.net/tracker/index.php?func=detail&aid=686577&group_id=40712&atid=428708)


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