Comments on: Improving Performance via Eager Fetching in Hibernate http://www.basilv.com/psd/blog/2008/improving-performance-via-eager-fetching-in-hibernate Wed, 08 Feb 2012 03:57:22 +0000 hourly 1 http://wordpress.org/?v=3.3 By: Lucas http://www.basilv.com/psd/blog/2008/improving-performance-via-eager-fetching-in-hibernate/comment-page-1#comment-110131 Lucas Wed, 21 Jul 2010 14:28:56 +0000 http://www.basilv.com/psd/blog/2008/improving-performance-via-eager-fetching-in-hibernate#comment-110131 Hi, i found this article when searching a way to improve performance in a nullable one-to-one mapping. I understand hibernate needs to query the database to know its nullability, but it does it with subsequent selects. So, if i want to retrieve a list of entities that have 4 one-to-one associations, hibernate triggers 4 selects for each entity retrieved. I tried everything to make hibernate retrieve the associations in a single query (fetch='join' and outer-join='true') but i see no difference. Do you have an idea of how can i avoid the separate selects? Lucas Hi, i found this article when searching a way to improve performance in a nullable one-to-one mapping. I understand hibernate needs to query the database to know its nullability, but it does it with subsequent selects. So, if i want to retrieve a list of entities that have 4 one-to-one associations, hibernate triggers 4 selects for each entity retrieved. I tried everything to make hibernate retrieve the associations in a single query (fetch=’join’ and outer-join=’true’) but i see no difference. Do you have an idea of how can i avoid the separate selects?
Lucas

]]> By: Mike http://www.basilv.com/psd/blog/2008/improving-performance-via-eager-fetching-in-hibernate/comment-page-1#comment-109475 Mike Fri, 02 Jul 2010 00:11:18 +0000 http://www.basilv.com/psd/blog/2008/improving-performance-via-eager-fetching-in-hibernate#comment-109475 a better solution is to just write your own SQL, lot simpler and will perform a lot better! a better solution is to just write your own SQL, lot simpler and will perform a lot better!

]]> By: Carles Barrobés http://www.basilv.com/psd/blog/2008/improving-performance-via-eager-fetching-in-hibernate/comment-page-1#comment-109399 Carles Barrobés Wed, 30 Jun 2010 09:22:26 +0000 http://www.basilv.com/psd/blog/2008/improving-performance-via-eager-fetching-in-hibernate#comment-109399 Very useful article. I had run into the problem of duplicated rows, which also surprised me as default behavior. I found that if you want distinct to be applied to a Criteria query, you have to use... criteria.setResultTransformer(Criteria.DISTINCT_ROOT_ENTITY); ...before calling list(). Very useful article. I had run into the problem of duplicated rows, which also surprised me as default behavior.

I found that if you want distinct to be applied to a Criteria query, you have to use…

criteria.setResultTransformer(Criteria.DISTINCT_ROOT_ENTITY);

…before calling list().

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