Greg Stark <gsstark(at)mit(dot)edu> writes:
> On Wed, Jun 24, 2009 at 1:43 PM, Dave North<DNorth(at)signiant(dot)com> wrote:
> Why use "like" for a constant string with no % or _ characters? If you
> used = the planner might be able to come up with a better estimate.
Uh, it appears to me the string *does* contain _ characters; perhaps the
OP has neglected to escape those?
The planner does know enough to estimate LIKE with a fixed pattern as
being equivalent to =. I think it knew that even back in 8.1, but am
too lazy to look right now.
regards, tom lane