What is a question about this article? If the question is unanswerable, say "unanswerable".

The merger made Columbia and Epic sister labels to RCA Records, which was once owned by RCA which also owned CBS rival NBC. It also started the process of bringing BMG's Arista Records back under common ownership with its former parent Columbia Pictures, a Sony division since 1989, and also brought Arista founder Clive Davis back into the fold. Davis is still with Sony Music as Chief Creative Officer.

Sony has been a Columbia Pictures division since what year?
unanswerable