Flo,

I'm afraid I'm unable to duplicate your results. I'm comparing an insert into/SELECT ... union all against a insert into VALUES for 1000 rows. The UNION ALL technique is running consistently faster on my machine, which I would expect because it's a single INSERT, as Bruce already stated.

Whenever possible you want to handle entire sets of data, instead of individual rows. When you look at the execution plan of the SELECT/UNION ALL approach, it amounts to single insert fed by the scan of an internal table of constants.

Bob

P.S. I also find it much easier to type up quick examples like are used in this forum using the SELECT/UNION ALL format.