Add count of logical writes to SET STATISTICS IO and to Actual I/O Statistics in execution plans
Currently neither the output of SET STATISTICS IO nor the data captured in the Actual I/O Statistics property in execution plans expose the number of logical writes. For Insert, Update, Delete, and Merge operators, this is a minor nuisance; usually the number of logical writes is well known and it is definitely seldom surprising. But for operators that use worktables and workfiles, such as Table Spool or Hash Match, there currently is no way to see how many logical writes were used.
This can, for instance, cause a many-to-many Merge Join to show only a very low number of logical reads to the worktable because there were very few actual duplicates in the data, while hiding the perhaps millions of logical writes that may be an actual performance problem in the execution plan.