Re: Coster/planner and edge cases...

Tom Lane wrote:

>Michael Loftis <mloftis@wgops.com> writes:
>
>>Also I'd also like to know if there is a way to get the planner to burp 
>>out all the possible plans it considered before selecting a final plan 
>>or do I need to do a little surgery to get that done?
>>
>
>You can define OPTIMIZER_DEBUG but the interface leaves a lot to be
>desired (output to backend stdout, no way to turn it on or off except
>recompile...)  Also, I believe all you will see are the paths that
>survived the initial pruning done by add_path.  This is about the
>right level of detail for examining join choices, but perhaps not very
>helpful for why-didn't-it-use-my-index choices; the paths you wanted
>to know about may not have got into the relation's candidate-path list
>in the first place.
>
Alright, that gives me some places to attack it at then anyway.  Thanks 
very much Tom.  Sounds like I'll probably be doing a little bit of work 
IE I'd like to have the information come back as say a notice or maybe 
as extra information for an EXPLAIN for my purposes, but unless there is 
interest, consensus on how it should be done, and a TODO item made of 
it, I won't be making a patch of that, no reason to clutter the backend 
with stuff that hopefully won't be needed for long :)

Michael