sp_update stats has threshold of rows that must have been changed since the last stats update for it to update them again. As Grant says in his article
then, you run sp_updatestats… Which will go through the whole table, determining if any data has changed and the statistics need to be updated. “Any data” reads, one row. So if even a single row has been modified since the last time the statistics were updated
Yes, that threshold is a single row.
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability