if query and mv def is as following:
def mv1_1 = """
select t1.L_LINENUMBER,t2.l_extendedprice, t2.L_ORDERKEY
from lineitem t1
inner join lineitem t2 on t1.L_ORDERKEY = t2.L_ORDERKEY;
"""
def query1_1 = """
select t1.L_LINENUMBER, t2.L_ORDERKEY
from lineitem t1
inner join lineitem t2 on t1.L_ORDERKEY = t2.L_ORDERKEY;
"""
this will generate relation mapping by Cartesian, if the num of self join is too much, this will cause the performance problem
so we add `materialized_view_relation_mapping_max_count` session varaible, default 8. if actual num is greater than the value, the excess relation mapping is discarded.
62998719df