Re: Find min and max values across two columns?

On Mon, 2006-05-15 at 16:40, Emi Lu wrote:
> Hello,
> 
> I tried "select greatest(max(a), max(b)) from public.test",  but I got 
> the following errors:
> 
> ERROR:  function greatest(integer, integer) does not exist
> HINT:  No function matches the given name and argument types. You may 
> need to add explicit type casts.
> 
> May I know where I can read the docs about greatest & least please.
> 
> I am using  PostgreSQL 8.0.7.

You need to define your problem better.  Assuming these data:

a  b
12 24
24 12
13 18
25 10

which should I get for greatest(max(a), max(b)) should I get?  Do you
just want 25,24???  In that case you don't need greatest.  Do you need
the highest total between the two, or what?