Re: We find few queries running three times simultaneously with sameparameters on postgres db

Em 26/06/2018 14:26, amandeep singh escreveu:
> Hi Andreas
>
> The value for $1 is same in all queries.
>
> @Edson: number of such running queries are always  3.

I see. It seems a programming logic error to me.
I also use JPA (Hibernate and/or EclipseLink) and I don't have such problem.
But I could replicate your scenario doing the following (with 
EclipseLink, didn't test with Hibernate):

1) In persistence.xml, disable all caches (this is very important for 
make reproducible)
2) Load three Person records that live on same city (objects Person and 
City mapped to tables Person and City, being city an attribute of Person 
object):

TypedQuery<Person> qry = em.createQuery("select P from Person P where 
P.city.name = :cityname");
qry.setParameter("cityname", "Porto Alegre");
qry.setMaxResults(3);
List<Person> rs = qry.getResultList();

3) This will cause one query against Person table, and exactly 3 queries 
issued with same parameters to City table.

I really don't know how your code works, and is quite hard to guess, but 
as you can see, it is easy to reproduce similar behavior.
Now, if I enable EclipseLink caches, only one query is issued for each 
City key - so, I'll have one query for Person and one query for  only.

Hope this helps to enlighten your problem.

:-)

Regards,

Edson