sybase - Is there any performance difference between count(*) and count(1)

Question

Query 1:

SELECT COUNT(1) FROM STUDENTS

Query 2:

SELECT COUNT(*) FROM STUDENTS

Both the queries return the same result, but is there any performance difference between these two ?

What I had heard is the first query would be faster than the second one, but can any one give specific details about it?

Answer 1

You may use count(*) or count(1) , one is not faster than the other. As stated, is just a urban legend :)

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One final note, count(*) and count(columnName) may be different!
The first one counts all rows, the second one counts the number of rows where the specified column is not NULL.

Answer 2

There is no difference whatsoever between the two statements.

The rumour that count(1) is faster is an urban legend that was never true.