Hi Lars,
count(*) iterates through the rows. I don't think it's any faster than
count( colName ).
-Rick
Lars Clausen wrote:
On Thu, 2005-11-10 at 04:41, Jeffrey Lichtman wrote:
1) A null column is excluded from a COUNT( colName ) aggregate. This
is described in the section 10.9 under General Rules 4a. The
database is supposed to raise a warning: "warning--null value
eliminated in set function"
If you want to get the count including nulls, you can use COUNT(*),
which returns the number of rows in the set being aggregated (not the
number of values).
A side question: Is this any faster than using COUNT( colName)? Or
does COUNT() always entail something on the order of iterating through
all the results of the query?
-Lars
