sql planner creates cross join instead of inner join from select predicates #1293

❯ create table part as select 1 as p_partkey;                                                                                                                                                
0 rows in set. Query took 0.003 seconds.                                                      
❯ create table lineitem as select 1 as l_partkey, 2 as l_suppkey;                             
0 rows in set. Query took 0.005 seconds.                                                      
❯ create table supplier as select 1 as s_suppkey;                                             
0 rows in set. Query took 0.002 seconds.                                                                                                
❯ explain select * from part, supplier, lineitem where p_partkey = l_partkey and s_suppkey = l_suppkey;                                                                                      
+---------------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------
--------------------------------------------------+                       
| plan_type     | plan                                                                                                                                                                                                                         |               
+---------------+----------------------------------------------------------------------------------------------------------------------------------------------------------------------------
--------------------------------------------------+  
| logical_plan  | Projection: #part.p_partkey, #supplier.s_suppkey, #lineitem.l_partkey, #lineitem.l_suppkey                                                                                 
                                                  | 
|               |   Join: #part.p_partkey = #lineitem.l_partkey, #supplier.s_suppkey = #lineitem.l_suppkey                                                                                   
                                                  |                                           
|               |     CrossJoin:                                                                                                                                                                                                               |                          
|               |       TableScan: part projection=Some([0])                                  
                                                  |                                                                                                                                          
|               |       TableScan: supplier projection=Some([0])                                                                                                                             
                                                  |                                                                                                                                          
|               |     TableScan: lineitem projection=Some([0, 1])      

❯ explain select * from part join lineitem on l_partkey = p_partkey join supplier on s_suppkey = l_suppkey;
+---------------+----------------------------------------------------------------------------------------------------------------------------------------------------+
| plan_type     | plan                                                                                                                                               |
+---------------+----------------------------------------------------------------------------------------------------------------------------------------------------+
| logical_plan  | Projection: #part.p_partkey, #lineitem.l_partkey, #lineitem.l_suppkey, #supplier.s_suppkey                                                         |
|               |   Join: #lineitem.l_suppkey = #supplier.s_suppkey                                                                                                  |
|               |     Join: #part.p_partkey = #lineitem.l_partkey                                                                                                    |
|               |       TableScan: part projection=Some([0])                                                                                                         |
|               |       TableScan: lineitem projection=Some([0, 1])                                                                                                  |
|               |     TableScan: supplier projection=Some([0])