Most Efficient (Fast) T-SQL DELETE For Many Rows?

Question

Our server application receives information about rows to add to the database at a rate of 1000-2000 rows per second, all day long. There are two mutually-exclusive columns

Answer 1

Maybe:

DELETE FROM MyRecords
WHERE  tag IN (1, 2, 555) -- build a list
OR longTag IN ('LongTag1')

I suspect indexes would help your deletes but drastically slow your inserts, so I wouldn't play with that too much. But then my intuition isn't exactly perfect yet, you might be able to tune FillFactor or other items to get around that issue, and the one thing I do know for sure it that you really want to profile both anyway.

Another option is to load new inserts into a temp table (named something like InputQueue), and then join the temp table on MyRecords to handle filtering updates. This would also make it easy to do the update in two steps: you could delete Tags and longTags as separate operations and that might turn out to be much more efficient.