Re: nested loop semijoin estimates

On 06/02/15 21:39, Tom Lane wrote:
> I wrote:
>> I'm a bit disturbed by that, because AFAICS from the plans, these queries
>> did not involve any semi or anti joins, which should mean that the patch
>> would not have changed the planner's behavior.
>
> After contemplating my navel for awhile, it occurred to me that maybe the
> patch's changes in add_path_precheck could have caused behavioral changes
> at the margins.  Could you try a run without that (without the last two
> hunks in pathnode.c)?

Yes, I think that's the cause. See the end of the message I sent just 
before you posted this.


--
Tomas Vondra                  http://www.2ndQuadrant.com
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