[BUGS] BUG #5542: Query optimization problem

[Roman]

The following bug has been logged online:

Bug reference:      5542
Logged by:          Roman
Email address:      zo...@oe-it.ru
PostgreSQL version: 9.0
Operating system:   Win7 x64
Description:        Query optimization problem
Details: 

I have a query:

SELECT d1.ID, d2.ID
FROM DocPrimary d1
  JOIN DocPrimary d2 ON d2.BasedOn=d1.ID 
WHERE (d1.ID=234409763) or (d2.ID=234409763)

i think what QO(Query Optimizer) can make it faster (now it seq scan and on
million records works 7 sec) 

SELECT d1.ID, d2.ID
FROM DocPrimary d1
  JOIN DocPrimary d2 ON d2.BasedOn=d1.ID 
WHERE (d2.BasedOn=234409763) or (d2.ID=234409763)

Result of this query are identical (and can get by replace part of where use
join dependence)
And it works 0-10ms

I think, what QO can undertstand it self.

Table create query:

CREATE TABLE docprimary
(
  id integer NOT NULL,
  basedon integer,
  CONSTRAINT id_pk PRIMARY KEY (id)
);

CREATE INDEX basedon_idx
  ON docprimary
  USING btree
  (basedon);

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