If your database supports ANSI or
Oracle style outer joins, outer join
fetching might increase performance by
limiting the number of round trips to
and from the database (at the cost of
possibly more work performed by the
database itself ). Outer join fetching
allows a graph of objects connected by
many-to-one, one-to-many or one-to-one
associations to be retrieved in a
single SQL SELECT .
I am trying to decide whether I should use outer join extraction (using NHibernate) in my current project. For this, I will use and not use outer join extraction to test the load time. But I want to know the overall good or bad strategy when using Sql Server 2008.
Is it usually better to use outer join extraction than to use Sql Server 2008?
How to determine whether to use it? (Except for performance testing and query analysis)
Thank you
Use outer join extraction when necessary; some queries will require outer join extraction on certain entities. Other queries will not. Therefore, if you don’t need it, please don’t rush to use outer joins.
You You can specify the extraction type for each association when using the ICriteria API.
This is an optimization problem and can be done later. I mean: suppose you have an object graph, some of which Part of it is retrieved by lazy loading, and after testing, if lazy loading seems to affect the performance of that particular object graph in some negative way, please check if you can get something to load by using eager (get fi via external connection).
When extracting external connections, the Nhibernate documentation says:
If your database supports ANSI or
Oracle style outer joins, outer join
fetching might increase performance by
limiting the number of round trips to
and from the database (at the cost of
possibly more work performed by the< br> database itself). Outer join fetching
allows a graph of objects connected by
many-to-one, one-to-many or one-to-one
associations to be retrieved in a
single SQL SELECT.
I am trying to decide whether I should use outer join extraction (using NHibernate) in my current project. For this, I will use and not use outer join extraction to Test the load time. But I want to know whether the overall strategy is good or bad when using Sql Server 2008.
Using outer join extraction is usually better than using Sq l Is Server 2008 better?
How to determine whether to use it? (Except for performance testing and query analysis)
Thank you
Weird problem.
Use outer join extraction when necessary; some Some queries will require outer join extraction on certain entities. Other queries will not. Therefore, if you don’t need it, please don’t rush to use outer joins.
You can specify extraction for each association when using ICriteria API Type.
These are all optimization problems and can be done later. I mean: suppose you have an object graph, some parts of which are retrieved by lazy loading, and after testing , If lazy loading seems to affect the performance of that particular object graph in some negative way, please check if you can get something to load by using eager (get fi via external connection).
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