For example, I have table
A with 80 million rows and table
B with 200 million rows.
Assume both tables have 30+ stat tables (all manually generated by SQL Server). I randomly take the first 10 stat tables from each and run the two tasks separately:
Update Statistics A (stat1, stat2, ...) with sample 5000000 rows Update Statistics B (stat1, stat2, ...) with sample 5000000 rows
Even though both are scanning 5000000 rows only, the second task is taking much longer to complete. Is this difference in performance solely from the difference in the contents of the tables, or does the number of rows in the table also play a part even if we are limiting the number of rows to scan?