Hmm, odd.

Im interested in this part of the plan

Which is pretty much the very first join between datasource and trade.

The estimate from the hash join is 1 , the actual row count is 465,002 !

Not much of a difference.

2005 is getting a bit old now as is my memory of its differences over 2008/2012.

You may be better of 'caching' the result of this join into a temp table and driving the rest from that.

Edit:

Just to elaborate on why this is bad :

As it thinks that there is 1 row, it has chosen to do loop joins to the other tables in the plan.

This would be good if there were 1 row but theres not, theres 465,000.

If it knew there were 465,000 it would have chosen a hash (or merge) join which will be more efficient

Dave