Sammy Davis, Jr. was a legendary entertainer in both Reno and Las Vegas during the 1950s and 1960s. Sammy was so popular, in fact, he was included in the holosuite program Bashir 62, a 24th century rendition of 1962. At the time, he was close friends with Frank Sinatra, Dean Martin, Peter Lawford, Joey Bishop, and was incorporated as a "tight" friend of Vic Fontaine's.
Upon telling Ezri Dax this, Ezri interpreted it as a ploy by Vic to use Sammy to convince Nog that it was time to leave the holosuite, Nog's chosen rehabilitation facility following the loss of his leg. Ezri's revelation, however, was not Vic's intention, which ultimately forced Vic to cancel his trip to see Sammy perform and realize that he needed to confront Nog about overstaying his holosuite visit. (DS9: "It's Only a Paper Moon")