OutOfMemory

tcn · **Joined:** Tue Mar 23, 2004 4:18 pm **Posts:** 45

Hi!

I select a fairly large amount of data from the database. More than fits into java heap space: OutOfMemory.

Is Hibernate smart enough to progressively fetch the data from database or will I have to do this myself but running multiple queries setting setMaxResults()/setFirstResult()?

What is the smartest way here?

nitz_tech · **Joined:** Wed Mar 17, 2004 12:44 am **Posts:** 25

does it mean that your result set is very big that it cannot fit into java heap ?

nitin

tcn · **Joined:** Tue Mar 23, 2004 4:18 pm **Posts:** 45

nitz_tech wrote:

does it mean that your result set is very big that it cannot fit into java heap ?

nitin

Yes (i.e. too many rows).

emmanuel · **Posted:** Fri Mar 26, 2004 3:31 pm

tcn wrote:

Is Hibernate smart enough to progressively fetch the data from database or will I have to do this myself but running multiple queries setting setMaxResults()/setFirstResult()?

It's not an Hibernate issue,
Hibernate is expected to build a list containing the results, so it cannot deference them.

tcn · **Joined:** Tue Mar 23, 2004 4:18 pm **Posts:** 45

emmanuel wrote:

tcn wrote:

Is Hibernate smart enough to progressively fetch the data from database or will I have to do this myself but running multiple queries setting setMaxResults()/setFirstResult()?

It's not an Hibernate issue,
Hibernate is expected to build a list containing the results, so it cannot deference them.

...but an JDBC driver issue?

So, you would propose a manual setFirstResult()/setMaxResulsts() solution (IMHO Hibernate could be somewhat more convinient about this :) ?

Martin Kersten · **Joined:** Tue Mar 16, 2004 5:15 am **Posts:** 33

Isn't an iterator suitable or does Hibernate only iterates through an underlying result list? I thought an iterator is implemented like a cursor of the result set... .

tcn · **Joined:** Tue Mar 23, 2004 4:18 pm **Posts:** 45

Martin Kersten wrote:

Isn't an iterator suitable or does Hibernate only iterates through an underlying result list? I thought an iterator is implemented like a cursor of the result set... .

That's what I meant by "more comfortable". Something like:

setPageSize(10).iterate()

which does automatically setMaxResults(10) and repeat setFirstResult()..