My apologies if this is in the docs somewhere, I was unable to find anything, but I might be calling it the wrong name.
I'm doing a full outer join in Pig - as such, one or the other join keys may be null. I'd like to be able to look at 2 columns, and retrieve just the one that is not null. Is that possible? I tried an expression in generate with is null and the ternary operator, and took a look at DECODE. That might do the trick but wasn't sure if null checking would work, and if other expressions could appear inside the decode. In my case the fields are integers, so I abused the MAX and TOBAG operators like this MAX(TOBAG(rx_keyed::u2,cx_keyed::u2)) to get the effect I was after, but I would love to know if there's a better way. Thanks for your time! -James Kebinger
