Eclipse Community Forums: BIRT » Can't execute Statement because of to many operations

Help

Home

Home » Archived » BIRT » Can't execute Statement because of to many operations

Show: Today's Messages :: Show Polls :: Message Navigator

Can't execute Statement because of to many operations [message #488086]

Fri, 25 September 2009 14:20

Michael ück

Messages: 8
Registered: July 2009

Junior Member

Hi,

I'm creating a BIRT report on an datasource that's linked to an mysql Cluster.

The Query of the DataSet is quite complicated and uses some joins and other stuff.

Everything works fine until i have a quite large dataset (sorry i have no concrete figures at the time.)

But the real problem seems to be that mysql cluster is not very good at large transactions. Because if the statement produces a large dataset the report gives an exception saying "Cannot execute the statement".

Looking at the XML Source of the report i can find an Error Marker saying that the query didn't return a ResultSet. The Concrete mysql-connector exception, which is the root-cause, says:

 SQL error  #1: Got temporary error 233 'Out of operation records in transaction coordinator (increase MaxNoOfConcurrentOperations)' from NDBCLUSTER

The Problem seems to be that query executed by BIRT runs in only one transaction and locks to many rows, which mysql-cluster can't handle.
See: http:// dev.mysql.com/doc/refman/5.0/en/mysql-cluster-limitations-tr ansactions.html

My question is now: Is there any way to activate autocommit or to run an query chunk by chunk?

thanks in advance,
Michael

Report message to a moderator

Re: Can't execute Statement because of to many operations [message #488749 is a reply to message #488086]

Wed, 30 September 2009 06:31

Michael ück

Messages: 8
Registered: July 2009

Junior Member

Don't know if somebody is interested in this but just in case.

The problem is that my database contains TEXT columns, which are handled as BLOBs by mysql-cluster. Because of that a SELECT statement creates a read-lock on every row it finds in the database.

By default mysql-cluster has a maximum number of read-locks (MaximumNumberOfCOncurrentOperations) of approx. 32000. And that's not enough if the report-query examines a large table.

If possible one should remove the BLOBS from the schema and replace them by an normal varchar or char.
If that's not possible increase MaximumNumberOfConcurrentOperations.

But that's what one can do on the database. If someone's got an idea for a workaround on BIRT-side i'd like to hear of it.

Report message to a moderator

Re: Can't execute Statement because of to many operations [message #488888 is a reply to message #488749]

Wed, 30 September 2009 15:31

Jason Weathersby

Messages: 9167
Registered: July 2009

Senior Member

Michael,

I do not know of a work around but I would like you to open a bugzilla
entry so we know the problem exist.

Thanks

Jason

Michael L wrote:
> Don't know if somebody is interested in this but just in case.
>
> The problem is that my database contains TEXT columns, which are handled
> as BLOBs by mysql-cluster. Because of that a SELECT statement creates a
> read-lock on every row it finds in the database.
> By default mysql-cluster has a maximum number of read-locks
> (MaximumNumberOfCOncurrentOperations) of approx. 32000. And that's not
> enough if the report-query examines a large table.
>
> If possible one should remove the BLOBS from the schema and replace them
> by an normal varchar or char. If that's not possible increase
> MaximumNumberOfConcurrentOperations.
>
> But that's what one can do on the database. If someone's got an idea for
> a workaround on BIRT-side i'd like to hear of it.

Report message to a moderator