Out of Memory error caused by huge result set

Question

Hi,
I'm using version 3.3.4 of KODO with the enterpise license. Our
application has some places where we're using straight SQL to create a
query using the following statement:
Query query = pm.newQuery ("javax.jdo.query.SQL", queryString);
There is one query that performs an inner join and returns over 2 billion
results. Of course this throws an out of memory error when we try to add
the results to a list. I printed out the exact SQL statement that is
being executed and it should return 0 results. The application is hitting
an Oracle 9i database, and running the query through the Oracle tool
SQLPlus returns the correct result. I'm stumped as to why this massive
result set is being returned when we use KODO. Here is the SQL string for
your examination:
SELECT T_ORDERITEM.* FROM T_ORDERITEM INNER JOIN T_REVENUE ON
T_ORDERITEM.ORDER_HOID = T_REVENUE.HOID WHERE T_ORDERITEM.COMMODITY_HOID
= '1871816913731466' AND T_ORDERITEM.DATESHIPPED BETWEEN
TO_DATE('12/25/2005', 'MM/DD/YYYY') AND TO_DATE('01/24/2006',
'MM/DD/YYYY') AND T_REVENUE.CUSTOMER_HOID IN (1844203535241210)
Thanks for your help,
Bennett

Answer 1

I'm also using JDK 1.4.2 so I'm not sure why you wouldn't be running into
the issue using the ArrayList constructor.
-Bennett
Paul Mogren wrote:
What result list implementation are you using? What's your JDK
version? I'm sure I've written new ArrayList(results) numerous times
without trouble, though I have not used Kodo 3.3.4. I had a look at
the JDK 1.4.2 source code for ArrayList(Collection) and
ArrayList.addAll(Collection), and it looks to me like the latter would
consume more memory than the former. However, it might be worth noting
that the former invokes size() on the argument.
-Paul Mogren, CommerceHub
On Thu, 19 Jan 2006 22:10:50 +0000 (UTC), [email protected]
(Bennett Hunter) wrote:
Nevermind, issue resolved. This wasn't due to the query, but rather how
we were creating a list with the results returned. This issue is probably
already posted, but I'll give the info. again:
You can't create an arraylist by passing in the kodo collection of results
to the constructor of ArrayList. For example: List l = new
ArrayList(results) .... that will throw the out of memory error because of
the way that the constructor builds the kodo collection. Maybe the bug is
with the kodo collection. However, the way around this is to create the
list with an empty constructor and then do an addAll() operation.
Bennett Hunter wrote:
Hi,
I'm using version 3.3.4 of KODO with the enterpise license. Our
application has some places where we're using straight SQL to create a
query using the following statement:
Query query = pm.newQuery ("javax.jdo.query.SQL", queryString);
There is one query that performs an inner join and returns over 2 billion
results. Of course this throws an out of memory error when we try to add
the results to a list. I printed out the exact SQL statement that is
being executed and it should return 0 results. The application is hitting
an Oracle 9i database, and running the query through the Oracle tool
SQLPlus returns the correct result. I'm stumped as to why this massive
result set is being returned when we use KODO. Here is the SQL string for
your examination:
SELECT T_ORDERITEM.* FROM T_ORDERITEM INNER JOIN T_REVENUE ON
T_ORDERITEM.ORDER_HOID = T_REVENUE.HOID WHERE T_ORDERITEM.COMMODITY_HOID
= '1871816913731466' AND T_ORDERITEM.DATESHIPPED BETWEEN
TO_DATE('12/25/2005', 'MM/DD/YYYY') AND TO_DATE('01/24/2006',
'MM/DD/YYYY') AND T_REVENUE.CUSTOMER_HOID IN (1844203535241210)
Thanks for your help,
Bennett