Re: [eclipselink-users] Performance degarde on using caching option

[Kiran Kumar Gubbi <kiran.kumar@xxxxxxxxxx>]

The original query used to get the sample detail for every request from the
database using NamedNativeQuery and no cache annotations are added to Sample
entity.


@NamedNativeQuery
 (
      name = Sample.FIND_PROPERTY_BY_KEY,
      query = "select * from Sample "
	+ "where NonPromaryKeyProperty1= ?1 and NonPromaryKeyProperty2 = ?2 "
             + "or NonPromaryKeyProperty1 = ?1 and NonPromaryKeyProperty2 is
null "
	+ "and not exists ( select 1 from property_tbl "
	+ "where NonPromaryKeyProperty1 = ?1 and NonPromaryKeyProperty2 = ?2 )",
     resultClass = Sample.class

)

and the DAO method is 


public String getProperty( final String NonPromaryKeyProperty1, final String
NonPromaryKeyProperty2)
{
       Query query = em.createNamedQuery( Sample.FIND_PROPERTY_BY_KEY );
       query.setParameter( 1, NonPromaryKeyProperty1);
       query.setParameter( 2, NonPromaryKeyProperty2);
       try
       {
	Sample prop = ( Sample) query.getSingleResult();
	return prop != null ? prop.getPropertyValue() : null;
        }
        catch ( NoResultException e )
        {
	return null;
        }
        catch ( NonUniqueResultException e )
       {
	throw new RuntimeException( "Multiple properties found with key: "	+
NonPromaryKeyProperty1
             + " and scheme: " + NonPromaryKeyProperty2, e );
        }

}


If I want to use cache to imporove the performace what's the better way of
implementing ?


Thanks,
Kiran


christopher delahunt wrote:
> 
> Are you indicating that there is problem, or just trying to explain your 
> results?
> 
> More information is required.  Is there a reason you are using the 
> checkCacheOnly option instead of the default?  What are you using for 
> the original query as a comparison?  If you mean the original query was 
> a straight SQL select that goes to the database compared to this, the 
> SQL query will go to the database and the rows returned used to get the 
> objects from the cache.  This current query will not hit the database at 
> all, due to the checkCacheOnly option being used.  Instead, it will go 
> through every single Sample object it has in the cache and check to see 
> if the NonPromaryKeyProperty1.equals("kk") and 
> NonPromaryKeyProperty2.equals("jj") until it finds what it is looking 
> for.  The speed this is done is affected by the processor, application 
> load and the number of objects in the cache, even the how the JVM 
> implements string comparisons.  At some level of JVM load, at some 
> number of objects in the cache etc, it will be expected that the in 
> memory query will be slower than a query that uses the database.  Using 
> a more powerful processor on a JVM with no load and infinite resources 
> in a cache of very limited size (say 1 object), I might expect the in 
> memory query to be faster - assuming the java string comparisons can be 
> done faster than the time it requires to send a JDBC statement to the 
> database and get a result back.  There are better options to use for 
> performance depending on what you are attemping.
> 
> Best Regards,
> Chris
> 
> 
> 
> 
> 
> On 23/07/2010 10:32 AM, Kiran Kumar Gubbi wrote:
>> After changing queries from nativequery to sessionquery the performance
>> of
>> the application drastically degraded. Used the following setting for
>> entity
>> and data access object for caching.
>>
>> Entity class 
>>
>> @Cache(
>> 		type = CacheType.SOFT, 
>> 		shared = true,
>> 		size = 10000,
>> 		coordinationType = CacheCoordinationType.SEND_OBJECT_CHANGES
>> )
>>
>>
>> DAO method ( before calling this methops List of sample objects are
>> available in cache)
>>  
>> public Sample getSample() {
>>   Sample sample = new Sample();
>>   sample.setNonPromaryKeyProperty1("kk");
>>   sample.setNonPromaryKeyProperty2("jj");
>>
>>   ReadObjectQuery query = new ReadObjectQuery( Sample.class );
>>   query.setExampleObject( sample);
>>   query.checkCacheOnly();
>>
>>   return ( Sample ) session().executeQuery( query );
>> }
>>
>> This change has degraded performance by 3 times.  Any suggestion please.
>>
>>
>> Kind regards,
>> kiran
>>
>>   
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> 

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