What is the advantage of using varbinary over varchar here?
A while ago I asked a question about hierarchy/version number sorting in SQL Server. ( How Can I Sort A 'Version Number' Column Generically Using a SQL Server Query).
Among the answers that were submitted was this link to a TSQL Coding challenge with much the same puzzle.
In the SQL2000 solution the author demonstrated a two variations, one using and returning a varchar and the other varbinary. The author explains THAT he is doing this without explaining WHY.
So, my question is really, what main differences/advantages (if any) of the difference in approach? I.e. why use a varbinary instead of a varchar?
I've omitted posting the code, as its most elegantly summed up in the above article.
Answer
I believe the expectation is that the varbinary data will generally consume fewer bytes (5), than the varchar one (10 or 11, I think) per portion of the original string, and so, for very large numbers of components, or comparisons to occur, it should be more efficient.
But I'd recommend that if you were looking to use either solution, that you implement both (they're quite short), and try some profiling against your real data (and query patterns), to see if there are practical differences (I wouldn't expect so).
(Crafty Steal): And as Martin points out, the binary comparisons will be more efficient, since it won't involve all of the code that's there to deal with collations. :-)