Prev: five-key syscaches
Next: [HACKERS] proposal - structured funcid and lineno as new fields in error message
From: Simon Riggs on 29 Mar 2010 04:33

We have planner method parameters for many important parts of the
planner. We don't have any parameter for join removal, AFAIK.

The first question I get asked is "can I see the tables it removed?".
This has been asked of me 3 times now this year, always first question.
Same issue applies to constraint exclusion.

But we *can* do this with constraint_exclusion, simply by turning it off
and checking the two outputs.

So I think we need a parameter for join removal also.

I don't want to turn it off, but I think we need a way for people to
check themselves that the removal of the joins is not an error. I
foresee many false bug reports along the lines of "optimizer ate my join
and I want it back".

--
Simon Riggs www.2ndQuadrant.com


--
Sent via pgsql-hackers mailing list (pgsql-hackers(a)postgresql.org)
To make changes to your subscription:
http://www.postgresql.org/mailpref/pgsql-hackers

 | 
Pages: 1
Prev: five-key syscaches
Next: [HACKERS] proposal - structured funcid and lineno as new fields in error message