Need all the columns pipeline using expression in mapper snap.

[dinkar]

when we use $.keys() below image which is showing list of columns for all the records which leads to performance issue (for example we have 1 lakh records, it will check for all 1 lakh records) ... Need only first row columns... Please help with expression which gives all columns for only 1 record.

[SpiroTaleski]

@dinkar 

Instead of going for all the rows, using the Head snap you will be able to get only first row and then get all the columns using keys() function.

[dinkar]

I need to know columns present in input pipeline

[SpiroTaleski]

@dinkar 

Check the Head Snap, you will be able to limit to a first row from the input stream, and then to get columns from that first row using the same function($.keys())