Forum Discussion
Can you talk more broadly about the problem you're trying to solve? If you went with this approach, then you could avoid doing for each row by routing a single document into the Mapper that finds the documents properties/column names.
I want to know list of columns using expression in mapper snap.
- When I write $.keys() expression its fetching all the columns for all the rows which to performance issue. I need only first document or first row.
- tlikarish2 years agoEmployee
How are you using those columns downstream from the mapper? One performance improvement would be to only do the call to $.keys() once and use that information. However if you need to join it with each document, then I'm not sure that would improve anything. If you only use it in some kind of load/write operation, then maybe that would be an improvement for you.