How merge stage works

[changming]

I was facing one preblem. the merge stage process two files. all filds are direct writen to a new output file. something I do not understand is some field in source is null become others field's value in target file. if I replace the null with 'NULL' in source, 'NULL' will be writen in target file correctly. IT seems that merge stage can not hanlde null string properly. Does any one know how merge stage work?

[ray.wurlod]

Can you please give a more detailed example, perhaps naming the source and target columns and telling us exactly what happens?

[us1aslam1us]

Does any one know how merge stage work?

You can know that by going through DataStage Online Manaual.

[vikrants]

I was facing one preblem. the merge stage process two files. all filds are direct writen to a new output file. something I do not understand is some field in source is null become others field's value in target file. if I replace the null with 'NULL' in source, 'NULL' will be writen in target file correctly. IT seems that merge stage can not hanlde null string properly. Does any one know how merge stage work?

Try setting the 'Nullable' type for those fields to 'Yes' in the 'Columns' tab of your Merge Stage. That should fix the problem.

[kumar_s]

Is it a fixed width file? That case, there is chance where the data extraction might be wrong. Merge doesn't shuffles the field values.