SIGSEGV and Partitioning

abhilashnair · Post by **abhilashnair** » Mon Mar 28, 2011 4:38 am

When a SIGSEGV error goes away when we change the configuration file from multiple node to single node, does this mean that the Partitioning is the culprit in this case. I have a job which fetches from ODBC and inserts into ODBC stage. The mode is Upsert(Update Then Insert). The job fails with SIGSEGV on 4 nodes and works fine on single node

priyadharsini · Post by **priyadharsini** » Mon Mar 28, 2011 5:33 am

what is the partition defined on ODBC stage?

abhilashnair · Post by **abhilashnair** » Mon Mar 28, 2011 6:52 am

priyadharsini wrote:what is the partition defined on ODBC stage?

Auto

chulett · Post by **chulett** » Mon Mar 28, 2011 7:08 am

Try hash partitioning on the key field(s) used in the upsert.

abhilashnair · Post by **abhilashnair** » Mon Mar 28, 2011 11:31 pm

chulett wrote:Try hash partitioning on the key field(s) used in the upsert. ...

Same Result even after Hash Partitioning. SIGSEGV error on target ODBC.
I have disabled Operator combination

ray.wurlod · Post by **ray.wurlod** » Tue Mar 29, 2011 2:00 am

How big (in bytes) are your rows?

Is the product of array size and row size too large to fit in memory?

abhilashnair · Post by **abhilashnair** » Tue Mar 29, 2011 3:44 am

ray.wurlod wrote:How big (in bytes) are your rows?

Is the product of array size and row size too large to fit in memory? ...

Array Size specified in Target is 2000. As for the Row Size, since this is a delete operation, The metadata of the target only has the key column. the Mode is Upsert/Delete Only

chulett · Post by **chulett** » Tue Mar 29, 2011 7:07 am

abhilashnair wrote:Array Size specified in Target is 2000.

As a test, lower it - even dropping it down to 1 to see if that makes any difference.

abhilashnair · Post by **abhilashnair** » Fri Apr 01, 2011 4:39 am

Dropped it to 1, it worked....too slow although...is this the only way ?

chulett · Post by **chulett** » Fri Apr 01, 2011 6:47 am

Did you try any other values, or just 1?

abhilashnair · Post by **abhilashnair** » Fri Apr 01, 2011 10:38 pm

Looks like, I need to go for trial and error here. Not sure, is there any other way to calculate exactly what should I mention in the Insert Array Size

chulett · Post by **chulett** » Fri Apr 01, 2011 11:02 pm

Nope, you hunt for the sweet spot - go up until it blows, then back it down a notch.