Where do you get the test harness from? Sorry I meant test data rather than test harness. regards david

Using the test harness I get the following stats (61160 row(s) affected) Table 'TC1_BIRDS'. Scan count 5, logical reads 3, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0. Table 'TC1_GRAINS'. Sca

This article sorts of explains it http://bradsruminations.blogspot.com/2010/03/this-article-on-recurson-is-entitled.html My understanding is that it prevents the input to a recursive cte from being evaluated lots of times. Instead it's spooled into a wo

I got (98 row(s) affected) Table 'Worktable'. Scan count 12438, logical reads 214967, physical reads 0, read-ahead reads 0, lob logical reads 0, lob physical reads 0, lob read-ahead reads 0. Table 'TC47'. Scan count 3, logical reads 162, physical read