Star Trek: 10 Things You Didn't Know About Miles O'Brien
4. A Happily Married Man
The script for Data's Day was originally pitched during The Next Generation's third season. At the time, it was a simple story that would follow 24 hours on board the Enterprise. However, Rick Berman and Michael Piller felt an episode-long plot arc was needed, thus leading to the Romulan spy character.
The other big event is the O'Briens' wedding. A couple of names were suggested before the writers settled on having O'Brien get hitched. Then, there was the question of to whom? At this stage, Wil Wheaton was leaving the show, and a new, female character was intended to replace him. In another universe, O'Brien would end up married to Ro Laren.
However, while Ro was being considered as a major new addition to the ship, no one wanted O'Brien to become someone's side-character, so this idea was quickly dropped. Keiko Ishikawa was then created. They would remain married for the rest of their time on The Next Generation and both would move over to Deep Space Nine.