Error when trying to start a Qlik task

[pmaclell]

Hi,

We are seeing the following error when trying to starting a Qlik task:

Encountered an unexpeceted error.
SqlStat: 42000 NativeError:8623 [Microsoft][ODBC Driver 18 for SQL Server][SQL Server]The query processor ran out of internal resources and could not produce a query plan. This is a rare event and only expected for extremely complex queries or queries that reference a very large number of tables or partitions. Please simplify the query. If you believe you have received this message in error, contact Customer Support Services for more information. (PcbMsg: 418)

The database we are using we are replicating 104 tables and some do have partitioned tables.

We are using the Log Stream when when creating our tasks.

Is this error being generted because Qlik is trying to perform operations under the covers and ran into issues with a particular table?

Are there any recommended troubleshooting steps to pinpoint what is causing this issue and try to reslove it?

Appreciate your time.

Thanks,

Paul

[john_wang]

Hello @pmaclell ,

Thanks for reaching out to Qlik Community!

The error pointed to a potential issue with the query itself in SQL Server, please check out the helpful link: Problem tracing Error: 8623 with extended events.

Quote:  The problem was that event size was to big so that it was dropped. You can check this by querying sys.dm_xe_sessions as e.g.

SELECT
  s.name,
  s.total_regular_buffers,
  s.regular_buffer_size,
  s.total_large_buffers,
  s.large_buffer_size,
  s.dropped_event_count,
  s.dropped_buffer_count,
  s.largest_event_dropped_size
FROM sys.dm_xe_sessions AS s;

If any event has been dropped you will se the number of dropped events in column dropped_event_count and the max size of any dropped event in largest_event_dropped_size. If this value is larger that the regular_buffer_size then you need to increase the regular buffer size.

Hope this helps.

Regards,

John.

[pmaclell]

Thanks John for your quick response!

Do we need to run this query at the time we are trying to start the task? 

Also, the link you provided doesn't work😁.

Thanks,

Paul

[john_wang]

Hello @pmaclell ,

Thanks for your feedback. Excuse me for the invalid link, I fixed it already.

I think you can run the query after the task failure.

Regards,

John.