Why such poor performance from same query in different databases
- Use a file sharing website, upload the .pesession file there (making sure to set access rights to public), then post a link here; or
- Upload the execution plans to www.pastetheplan.com, which presents the plans in a way that is easier to digest, but you can only upload the execution plan and not the .pesession file (which usually contains additional information).
Whichever option you choose, do make sure to share both the slow and the fast version of the execution plan, and to clearly indicate which is which. If available, please post output of set statistics io / time as well.
Oh, and just to make sure: when the slow query was running, did you check for locking and blocking?