The Lives of Dax anthology was first published in 1999, shortly after DS9 ended. It was a trade paperback novel (with a cream-colored cover, incidentally).
Rather, it was a trade paperback anthology. The term "novel" refers to a single fictional work at least 40,000 words in length. An anthology is not a novel, because it's a compilation of multiple shorter works. (Although there is such a thing as a "fix-up" novel which is essentially a collection of multiple stories by the same author, rewritten to form a loose story arc or connected by a framing structure. Asimov's original Foundation
trilogy and I, Robot
were fix-ups, as was Bradbury's The Martian Chronicles
. Granted, The Lives of Dax
does have a framing structure tying the stories together, but since they're by different authors, I think it lands on the anthology side of the line and not the fix-up side.)