Betr.: [eclipselink-users] Duration of a simple object query

[Willem Kunkels <Willem.Kunkels@xxxxxxxxxxxxxx>]

Holger,

In the database, do you have keys for
the fields you are doing the query on? The cache usage only has a purpose
when using the primary key for a record. Just another tip: precede the
named query name with the name of the class it is defined in (usally the
POJO of the return type), that makes it easier to find the named query
back.

regards,

Willem Kunkels
Java Developer

Koopman International BV
Distelweg 88
1031 HH  Amsterdam
The Netherlands
Tel.: +31 20 494 7 893
www.koopmanint.com

Holger Rieß <Holger.Riess@xxxxxxxxxxxxxxxxxx>

03-08-2009 16:01

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Onderwerp	[eclipselink-users] Duration of a simple object query

My query
                
...
                
Query query = em.createNamedQuery("findStockTableByItemNumber");
                
query.setParameter("itemnumber", itemNumber);
                
retStockTable = (Stocktable) query.getSingleResult();
                
...
needs about 15 ms if there is a record in the database and about 70 ms
if there is no record (profiler).

The named query is ...
@NamedQuery(name = "findStockTableByItemNumber", query = "SELECT
st FROM Stocktable st WHERE st.itemnumber =        
         :itemnumber AND st.dataset
= 'DAT' AND st.cKatalog = '001'", hints = {
                
                 @QueryHint(name
= QueryHints.CACHE_USAGE, value = CacheUsage.CheckCacheThenDatabase),
                
                 @QueryHint(name
= QueryHints.QUERY_TYPE, value = QueryType.ReadObject) }),
...

About 40% of my queries have no result - this is a great problem for the
performance of my application.
There is no additional code for the handling of NoResultException.
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