Jonah H. Harris wrote:
On Wed, May 21, 2008 at 10:10 AM, H. Hall <hhall1001@xxxxxxxxxxxxxx> wrote:
Does anyone know if there is a source that provides "Big O" notation for
postgres's aggregate functions and operations? For example is count(*) =
O(1) or O(n)?
I don't know of any document containing the complexity of each
aggregate, but it's sometimes left as a comment in the souce code.
Recent max() and min() can be O(n) or O(1) depending on the where-clause
and presence of an index too, just to muddy the waters.
--
Richard Huxton
Archonet Ltd