My job contains a DB2-API stage which reads data from a table containing 10,000 records and passes it to Sort stage. Then the sorted data is input to Aggregator stage and the output of Aggregator is written to Sequential Fille.
I want this job to be run on multiple nodes (Here i am simulating it on 1, 2, 4, 6 and 8 nodes) parallelly and test the performance.
For Sort and Aggregator stages, Default execution mode is set to 'Parallel'(I am using it as it is). But for DB2-API stage Default execution mode is set to 'Sequential' so i changed it to Parallel.
Issue:
1) When i run the job on 2 nodes, the DB2-API stage is actually reading 20,000 records(i.e 10,000*2) instead of 10,000 records..
When i run the job on 4 nodes, the DB2-API stage is actually reading 40,000 records(i.e 10,000*4) instead of 10,000 records.. and so on. Why?
2) For DB2-Enterprise stage, default Execution mode is Sequential. I can't change it to Parallel as it is disabled. Can't we run DB2-Enterprise stage in Parallel execution mode? Why?
3) Where as ODBC connector stage is having default Execution mode as Parallel. Any reason behind it?
Issue when 'Execution Mode' set to 'Parallel' for DB2-API
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Issue when 'Execution Mode' set to 'Parallel' for DB2-API
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The DB2-API stage will connect to the database via DB2 Connect and when changed to parallell it will open a connection per node therfore multiplying your data likewise (unless you have a patch for DPF with range partitions).1) When i run the job on 2 nodes, the DB2-API stage is actually reading 20,000 records(i.e 10,000*2) instead of 10,000 records..
When i run the job on 4 nodes, the DB2-API stage is actually reading 40,000 records(i.e 10,000*4) instead of 10,000 records.. and so on. Why?
Strange that its set to sequential!? However DB2EE-stage will run sequnatial if you have a user-defined SQL. It will also run sequential if you only have one node on your database...2) For DB2-Enterprise stage, default Execution mode is Sequential. I can't change it to Parallel as it is disabled. Can't we run DB2-Enterprise stage in Parallel execution mode? Why?
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http://it.toolbox.com/blogs/bi-aj
my blog on delivering business intelligence using agile principles