Skip to main content
Solved

Why does Field Renamer Stage perform worse than Expression Evaluator?


mblahay
Discovered Fame

I have encountered a situation where renaming fields using the Field Rename stage performs so poorly that it is much better to simply use the Expression Evaluator to make copies of the fields (524 in total) with the desired names. This baffles me as I expected the expression evaluator in this scenario to be more costly since it is duplicating the records. What is going on here that is making this so counter intuitive?

Best answer by saleempothiwala

@mblahay,

Yes, that would be a good option to use the final field name in expression evaluator so you dont have to process the same column multiple times during the batch

View original
Did this topic help you find an answer to your question?

5 replies

Bikram
Headliner
Forum|alt.badge.img+1
  • Headliner
  • 486 replies
  • October 14, 2022

@mblahay 

You can try the field mapper processor to rename the field names and i believe it will solve your problem.


mblahay
Discovered Fame
  • Author
  • Discovered Fame
  • 13 replies
  • October 17, 2022

How does one use the field mapper to rename all the fields? I think I understand how it works if all the fields are being renamed using a similar process, such as applying a prefix or suffix to all, but what if there isn’t a particular pattern to the renaming?


Bikram
Headliner
Forum|alt.badge.img+1
  • Headliner
  • 486 replies
  • October 17, 2022

@mblahay 

 

you can use field renamer or scripting  processor to rename it.

If don’t mind , kindly send me the case on which you are facing issues, so i can check on it.

 


mblahay
Discovered Fame
  • Author
  • Discovered Fame
  • 13 replies
  • October 24, 2022

I’m done some more testing and it doesn’t seem that the renamer is necessarily worse performing, but it isn’t a cheap operation either. For instance, if fields need to be renamed and those same fields need to be transformed, it appears to be better to create new fields with the new names in the expression evaluator where the transformations occur.


saleempothiwala
Headliner
Forum|alt.badge.img

@mblahay,

Yes, that would be a good option to use the final field name in expression evaluator so you dont have to process the same column multiple times during the batch


Reply