Have you ever had a table to a lot of rows, when I mean a lot I mean over 1,000,000 records.
If you try and perform a row count like
SELECT COUNT(ID) FROM table
it just takes forever.
If you are running SQL server you can perform a look up in the sysindexes table
WHERE id = OBJECT_ID(‘table‘)
AND indid < 2
much fast, but not so easy.