I have a query:

 

SELECT oh.id
FROM objects_hier oh
where
oh.id < 2000 (!)
and
oh.id in (
      SELECT id as id FROM objects_access oa
      WHERE
      oa.master IN (1,2,10001)
      AND
      oa.id < 2000 (!)

)

 

The sense of the query is simple: I choose ids from objects_hier where access has necessary masters.

 

The problem is: I have duplicate conditions for id here. They are marked with ‘!’.

 

I just can’t remove any of them, because planner needs to estimate both outer and inner selects to calculate the order

Of nested loop or choose a join. If I remove one of duplicate conditions – planner can’t estimate well.

 

It’s obvious that condition on oh.id can be put inside or outside “oh.id in ( .. )” statement with same result.

 

So I just suggest that the planner should take this into account and “propagate” the condition outside or inside for planning if needed.

 

P.S

Is there a way to fix this particular query? Usually oh.id condition is not like <2000, but an inner join.

 

 

 

 

 

 

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