Rajesh Kumar Mallah <mallah@trade-india.com> writes:
> Below are the plans for two cases. I dont know how to read them accurately
> can u please explain them.
Well, they're the same plan, as far as they go. I suppose that the
runtime difference must come from choosing a different plan inside the
most_recent_edition() function, which we cannot see in the explain
output. As before, turning on logging of verbose query plans is the
only way to look at what the function is doing.
> Also can anyone point to some documentation
> oriented towards understanding explain analyze output?
http://www.postgresql.org/docs/view.php?version=7.3&idoc=0&file=performance-tips.html
regards, tom lane