Hello,
One of my SQL is using two different execution paths in two different DB instances. The object definition, indexes etc. are same in both the instances. What could be the possible reason for the following discrepancy?

Query Plan in DB Instance 1:

Query Plan
------------------------------------------------------
SELECT STATEMENT Cost = 1180
HASH JOIN
TABLE ACCESS FULL Table_AAA
TABLE ACCESS FULL Table_BBB

Query Plan in DB Instance 2:

Query Plan
-----------------------
SELECT STATEMENT Cost = 1468
HASH JOIN
TABLE ACCESS FULL Table_BBB
TABLE ACCESS FULL Table_AAA

Thanks