Dataset warning-expecting 2 segments, read 3 segments.

[deepa.y]

Hi,
I have a sequence in which two parallel jobs are called in sequential manner.
First job will append to a dataset.
Second job reads from the above appended dataset and write to a sequential file.
When i run this job normally,i dont see any warnings.
If i run the job in parallel instances of 2 ,i see the below warning
Dataset: /home/TestFolder/fac.ds, expecting 2 segments, read 3 segments.
I guess this is because the first instance is trying to read the dataset while the second instance is appending the dataset.
Correct me if i am wrong.
Please let me know how can i overcome this warning ?

[chulett]

Don't run them in parallel. Never mind the fact that it doesn't make any sense to do that since one job is creating the source data the other job needs.

[ArndW]

Your analysis of the problem cause is correct. While datasets are very efficient for reading/writing data, they remain at heart sequential files (perhaps "sequential files on steroids" might be more fitting). They are not databases and, along with sequential files, are 1-Writer or N-Readers. There is no way to overcome the warning. Perhaps changing your design so that the second process creates and writes to a new dataset instead of appending, then performing the append at a time when no other process is using the original dataset.