What is difference between *.parameter , sid.__parameter and *.__parameter in RAC
*.java_pool_size=128M
*.__java_pool_size=384M
prdnw2.__java_pool_size=402653184
prdnw1.__java_pool_size=402653184
SQL> show parameter java_pool_size
NAME TYPE VALUE
------------------------------------ -------------------------------- ------------------------------
java_pool_size big integer 128M