CREATE TABLE TMP
(
  ID Integer NOT NULL,
  CONSTRAINT PK_TMP_1 PRIMARY KEY (ID)
);

CREATE VIEW TMP_VIEW (ID1, ID2)
AS
SELECT 1,(SELECT 1 FROM RDB$DATABASE) FROM RDB$DATABASE;


/*** With view + subselect column ***/

SELECT * FROM tmp_view TV LEFT JOIN tmp T ON T.id=TV.id2

> PLAN JOIN (TV RDB$DATABASE NATURAL, T NATURAL)

- PK_TMP_1 is not used.


/*** With view + normal column ***/

SELECT * FROM tmp_view TV LEFT JOIN tmp T ON T.id=TV.id1

> PLAN JOIN (TV RDB$DATABASE NATURAL, T INDEX (PK_TMP_1))

- PK_TMP_1 is used.


/*** Without view + subselect column ***/

SELECT * FROM RDB$DATABASE TV LEFT JOIN tmp T ON T.id=(SELECT 1 FROM RDB$DATABASE)

> PLAN JOIN (TV NATURAL, T INDEX (PK_TMP_1))

- PK_TMP_1 is used.



In FB 2.1.3 and FB 2.5 RC3 is PK_TMP_1 used.