Description
Let's assume DDL to be same for both the tables involved in a join
CREATE TABLE LeftTable ( id1 CHAR(6) NOT NULL, id2 VARCHAR(22) NOT NULL, id3 VARCHAR(12) NOT NULL, id4 CHAR(2) NOT NULL, id5 CHAR(6) NOT NULL, id6 VARCHAR(200) NOT NULL, id7 VARCHAR(50) NOT NULL, ts TIMESTAMP , CONSTRAINT PK_JOIN_AND_INTERSECTION_TABLE PRIMARY KEY(id1,id2,id3,id4,id5,id6,id7))
Following query return right results
SELECT m.*,r.* FROM LEFT_TABLE m join RIGHT_TABLE r on m.id3 = r.id3 and m.id2 = r.id2 and m.id4 = r.id4 and m.id5 = r.id5 and m.id1 = r.id1 and m.ts = r.ts where r.id1 IN ('201904','201905') and r.id2 = 'ID2_VAL' and r.id3 IN ('ID3_VAL','ID3_VAL2')
but When to optimize the query, filters for the left table are also added , query returned empty result . Though the filters are based on join condition so semantically above query and below query should be same.
SELECT m.*,r.* FROM LEFT_TABLE m join RIGHT_TABLE r on m.id3 = r.id3 and m.id2 = r.id2 and m.id4 = r.id4 and m.id5 = r.id5 and m.id1 = r.id1 and m.ts = r.ts where m.id1 IN ('201904','201905') and r.id1 IN ('201904','201905') and r.id2 = 'ID2_VAL' and m.id3 IN ('ID3_VAL','ID3_VAL2') and r.id3 IN ('ID3_VAL','ID3_VAL2')