The difference between select COUNT (*) and select COUNT (1)

In general, select COUNT (*) and select COUNT (1) both return the same result

If the table does not have a primary key (Primary key), then count (1) is faster than COUNT (*),

If there is a primary key, the primary key is the fastest when the condition of Count is the count (primary key)

If your table has only one field, then count (*) is the fastest

Count (*), like the result of Count (1), includes statistics for NULL, and Count (column) is a statistic that does not include null

The difference between select COUNT (*) and select COUNT (1)