Feat(optimizer): expand join constructs into SELECT * from subqueries

[georgesittas]

Fixes #1554

Click this to see the execution of all added test cases in both trino and postgres.

Trino

trino> WITH tbl AS (SELECT 1) SELECT * FROM (tbl AS tbl) AS _q_0; -- Only valid in Trino, postgres doesn't allow this
 _col0 
-------
     1 
(1 row)

trino> WITH tbl AS (SELECT 1) SELECT * FROM ((tbl AS tbl)) AS _q_0;
 _col0 
-------
     1 
(1 row)

trino> WITH tbl AS (SELECT 1) SELECT * FROM (((tbl AS tbl))) AS _q_0;
 _col0 
-------
     1 
(1 row)

trino> WITH tbl AS (SELECT 1) SELECT * FROM (SELECT * FROM tbl AS tbl) AS _q_0; -- optimized
 _col0 
-------
     1 
(1 row)

trino> WITH tbl1(id1) AS (SELECT 1), tbl2(id2) AS (SELECT 1), tbl3(id3) AS (SELECT 1) SELECT * FROM (tbl1 AS tbl1 JOIN tbl2 AS tbl2 ON id1 = id2 JOIN tbl3 AS tbl3 ON id1 = id3) AS _q_0;
 id1 | id2 | id3 
-----+-----+-----
   1 |   1 |   1 
(1 row)

trino> WITH tbl1(id1) AS (SELECT 1), tbl2(id2) AS (SELECT 1), tbl3(id3) AS (SELECT 1) SELECT * FROM ((tbl1 AS tbl1 JOIN tbl2 AS tbl2 ON id1 = id2 JOIN tbl3 AS tbl3 ON id1 = id3)) AS _q_0;
 id1 | id2 | id3 
-----+-----+-----
   1 |   1 |   1 
(1 row)

trino> WITH tbl1(id1) AS (SELECT 1), tbl2(id2) AS (SELECT 1), tbl3(id3) AS (SELECT 1) SELECT * FROM (SELECT * FROM tbl1 AS tbl1 JOIN tbl2 AS tbl2 ON id1 = id2 JOIN tbl3 AS tbl3 ON id1 = id3) AS _q_0; -- optimized
 id1 | id2 | id3 
-----+-----+-----
   1 |   1 |   1 
(1 row)

trino> WITH tbl1(id1) AS (SELECT 1), tbl2(id2) AS (SELECT 1), tbl3(id3) AS (SELECT 1) SELECT * FROM (tbl1 AS tbl1 JOIN (tbl2 AS tbl2 JOIN tbl3 AS tbl3 ON id2 = id3) AS _q_0 ON id1 = id3) AS _q_1;;
 id1 | id2 | id3 
-----+-----+-----
   1 |   1 |   1 
(1 row)

trino> WITH tbl1(id1) AS (SELECT 1), tbl2(id2) AS (SELECT 1), tbl3(id3) AS (SELECT 1) SELECT * FROM (SELECT * FROM tbl1 AS tbl1 JOIN (SELECT * FROM tbl2 AS tbl2 JOIN tbl3 AS tbl3 ON id2 = id3) AS _q_0 ON id1 = id3) AS _q_1; -- optimized
 id1 | id2 | id3 
-----+-----+-----
   1 |   1 |   1 
(1 row)

Postgres

georgesittas=# WITH tbl1(id1) AS (SELECT 1), tbl2(id2) AS (SELECT 1), tbl3(id3) AS (SELECT 1) SELECT * FROM (tbl1 AS tbl1 JOIN tbl2 AS tbl2 ON id1 = id2 JOIN tbl3 AS tbl3 ON id1 = id3) AS _q_0;
 id1 | id2 | id3
-----+-----+-----
   1 |   1 |   1
(1 row)

georgesittas=# WITH tbl1(id1) AS (SELECT 1), tbl2(id2) AS (SELECT 1), tbl3(id3) AS (SELECT 1) SELECT * FROM ((tbl1 AS tbl1 JOIN tbl2 AS tbl2 ON id1 = id2 JOIN tbl3 AS tbl3 ON id1 = id3)) AS _q_0;
 id1 | id2 | id3
-----+-----+-----
   1 |   1 |   1
(1 row)

georgesittas=# WITH tbl1(id1) AS (SELECT 1), tbl2(id2) AS (SELECT 1), tbl3(id3) AS (SELECT 1) SELECT * FROM (SELECT * FROM tbl1 AS tbl1 JOIN tbl2 AS tbl2 ON id1 = id2 JOIN tbl3 AS tbl3 ON id1 = id3) AS _q_0; -- optimized
 id1 | id2 | id3
-----+-----+-----
   1 |   1 |   1
(1 row)

georgesittas=# WITH tbl1(id1) AS (SELECT 1), tbl2(id2) AS (SELECT 1), tbl3(id3) AS (SELECT 1) SELECT * FROM (tbl1 AS tbl1 JOIN (tbl2 AS tbl2 JOIN tbl3 AS tbl3 ON id2 = id3) AS _q_0 ON id1 = id3) AS _q_1;
 id1 | id2 | id3
-----+-----+-----
   1 |   1 |   1
(1 row)

georgesittas=# WITH tbl1(id1) AS (SELECT 1), tbl2(id2) AS (SELECT 1), tbl3(id3) AS (SELECT 1) SELECT * FROM (SELECT * FROM tbl1 AS tbl1 JOIN (SELECT * FROM tbl2 AS tbl2 JOIN tbl3 AS tbl3 ON id2 = id3) AS _q_0 ON id1 = id3) AS _q_1; -- optimized
 id1 | id2 | id3
-----+-----+-----
   1 |   1 |   1
(1 row)

[georgesittas]

@barakalon thanks for the review! I did a refactor using transform instead of scopes. Let me know what you think.

[barakalon]

Much cleaner 👍