Re: many Union all vs. inserting results to temp table

Oh yeah, I forgot the part about unions doing sort and distincts. Quoting asktom:

"A union B union C

is really

distinct( sort( a + b + c ) )"

So at some point you would expect to see severe performance degradation as the sort segments get written to disk.

jg

--
@home.com is bogus.


"We have studies to prove it."

http://www.signonsandiego.com/uniontrib/20060322/news_1c22singular.html