Hello Castor team.
Sorry for the big letter.
I performed some benchmarks of Castor JDO and
got really bad results. The test case performed selection
of 100, 1000, 5000 and 10000 objects from the database (all results are in
milliseconds).
The code snapshot:
db = _jdo.getDatabase();
db.begin();
query = db.getOQLQuery( "SELECT c FROM "
+ Product.class.getName() + " c WHERE c.id < " + rowsNum );
t4 =
System.currentTimeMillis();
results = query.execute();
t5 =
System.currentTimeMillis();
while ( results.hasMore() )
{
prod = (Product) results.next();
}
t6 =
System.currentTimeMillis();
db.commit();
t7 =
System.currentTimeMillis();
db.close();
System.out.println( "execQuery:" + (t5-t4) );
System.out.println( "loop:" + (t6-t5) );
System.out.println( "commitTrans:" + (t7-t6) );
Results for 100 rows:
execQuery: 605
loop: 71
commitTrans: 70
Results for 1000 rows:
execQuery: 610
loop: 1112
commitTrans: 681
Results for 5000 rows:
execQuery: 601
loop: 25246
commitTrans: 15212
Results for 10000 rows:
execQuery: 761
loop: 105853
commitTrans: 65674
As you can see, the times for 100 and 1000 rows are "reasonable" while for
5000 or 10000 is too slow (comparing to direct JDBC).
So there are number of questions that the results raise:
Why looping over 1000 rows is 25 times faster than over 5000 rows (it should
by 1:5)?
How can I reduce looping time & commit time (may be there is some
settings/parameters)?
Why QueryResultsEnum is not serializable object, so there will no need to
copy it to another container?
Any suggestion/correction/answer is highly appreciated.
Additional info:
mapping for the class:
<class name="Product" identity="id">
<map-to table="prod" xml="product" />
<field name="id" type="integer">
<sql name="id" type="integer" />
<bind-xml name="id" node="attribute"/>
</field>
<field name="name" type="string">
<sql name="name" type="char" />
<bind-xml name="name" node="element" />
</field>
<field name="price" type="integer">
<sql name="price" type="integer" />
<bind-xml name="price" node="attribute" />
</field>
</class>
Class definition:
public class Product
{
private int _id;
private String _name;
private int _price;
public Product(){}
public int getId()
{
return _id;
}
public void setId( int id )
{
_id = id;
}
public String getName()
{
return _name;
}
public void setName( String name )
{
_name = name;
}
public int getPrice()
{
return _price;
}
public void setPrice( int price )
{
_price = price;
}
}
Best regards,
Mark.
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