nl_g_join

Specifies a nested-loop join of two or more derived tables.

( nl_g_join        ( derived_table1 )
                        ( derived_table2 )
        ...
                        ( derived_tableN )
)

A derived table that is the join of the specified derived tables.

select *
from t1, t2
where c21 = 0
and c22 = c12

( nl_g_join
    ( i_scan i_c21 t2 )
    ( i_scan i_c12 t1 )
)

Table t2 is the outer table, and t1 the inner table in the join order.

select *
from t1, t2, t3
where c21 = 0
and c22 = c12
and c11 = c31

( nl_g_join
    ( i_scan i_c21 t2 )
    ( i_scan i_c12 t1 )
    ( i_scan i_c31 t3 )
)

Table t2 is joined with t1, and the derived table is joined with t3.

The tables are joined in the order specified in the nl_g_join clause
The nl_g_join operator is a generic logical operator that describes all binary joins (inner join, outer join, or semijoin). The joins are performed using the nested-loops query execution method.