Martijn van Oosterhout <kleptog@svana.org> writes:
> On Thu, Jan 18, 2007 at 10:08:24PM +0100, Peter Kovacs wrote:
>> Are the plans cached per connection? Why not globally?

> Because global plan caching is much harder and nobody has done it yet?

The idea's been discussed before, and there are at least three problems
with it:

* unpredictability of shared-memory requirement

* plan cache would become a contention hot-spot

* much greater need for explicit cache management operations ("restart
your session" would no longer substitute for a flush-the-cache command)

                        regards, tom lane

---------------------------(end of broadcast)---------------------------
TIP 9: In versions below 8.0, the planner will ignore your desire to
       choose an index scan if your joining column's datatypes do not
       match

Reply via email to