CREATE TABLE users (
	login NAME NOT NULL PRIMARY KEY,
	datum TIMESTAMP,
	version INTEGER
);

CREATE TABLE test (
	datum TIMESTAMP NOT NULL,
	version INTEGER NOT NULL,
	approved TIMESTAMP
);

CREATE OR REPLACE VIEW v AS
	SELECT t.*
	FROM test AS t
	INNER JOIN users AS u ON
		t.datum <= u.datum AND
		(t.version = u.version OR
		 t.approved IS NOT NULL);

CREATE OR REPLACE FUNCTION fill () RETURNS BOOLEAN AS '
	DECLARE
		i INTEGER;
	BEGIN
		FOR i IN 1..1000 LOOP
			EXECUTE ''INSERT INTO test (datum,version)
				VALUES (now(),''|| i || '')'';
		END LOOP;
		RETURN TRUE;
	END;
' LANGUAGE plpgsql;

CREATE OR REPLACE FUNCTION approved () RETURNS BOOLEAN AS '
	DECLARE
		i INTEGER;
	BEGIN
		FOR i IN 1..1000 LOOP
			EXECUTE ''INSERT INTO test (datum,version,approved)
				VALUES (now(),''|| i || '',now())'';
		END LOOP;
		RETURN TRUE;
	END;
' LANGUAGE plpgsql;

SELECT fill();
SELECT fill();
SELECT fill();
SELECT fill();
SELECT fill();
SELECT fill();
SELECT fill();
SELECT fill();
SELECT fill();
SELECT fill();
SELECT fill();
SELECT fill();
SELECT fill();
SELECT fill();
SELECT fill();
SELECT fill();
SELECT fill();
SELECT fill();
SELECT fill();
SELECT fill();
SELECT approved();

INSERT INTO users (login,datum,version) VALUES ('sb',now(),'999');

CREATE INDEX test_ ON test (datum);
CREATE INDEX test_999 ON test (datum) WHERE version = '999' OR approved IS NOT NULL;

ANALYZE;

EXPLAIN ANALYZE SELECT * FROM v;
EXPLAIN ANALYZE SELECT t.* FROM test AS t INNER JOIN users AS u ON t.datum <= u.datum AND (t.version = '999' OR t.approved IS NOT NULL);