"Gurjeet Singh" <[EMAIL PROTECTED]> writes:
> In the plan below, we can see that the optimizer is sorting an already
> sorted result. It seems to forget the sort order across the UNIQUE node. My
> question is, do we make any attempts in the optimizer to remember the sort
> order of a result, to avoid any further sorting on same sort-key? If not,
> can we do something about it?
Per the comment in create_unique_path:
/*
* Treat the output as always unsorted, since we don't necessarily have
* pathkeys to represent it.
*/
pathnode->path.pathkeys = NIL;
No doubt this could be improved, but I'm unsure about the effort/reward
ratio.
regards, tom lane
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