When I try to create a statistics on a filestream column, I get the following error message:
Column 'MyColumn' in table 'MyTable' is of a type that is invalid for use as a key column in an index or statistics.
This is documented in the BOL page for CREATE STATISTICS and it's not an issue.
However, when I run a query with a predicate on the column (
IS NOT NULL, for the record), a statistics is auto-created. Why is this disallowed for manual creation but still possible for auto creation?
The reason why I want to create a statistics manually is that I want to mark it
NORECOMPUTE in order to avoid having to scan several GBs of data. I know I can let SQL Server auto create it and then mark it
NORECOMPUTE later, but auto creation is triggered with the default sample, which I could override to
0 ROWS in manual creation. I would also like to know if there is a reason for this.