是否可以在Oracle DBMS中升级Oracle JVM？

Question

I am trying to understand how the Embedded Oracle JVM works ( The JVM used to run Java Stored Procedures and Triggers ).

1. Is it possible to upgrade the existing embedded JVM?
2. Is it possible to configure Oracle RDBMS so that it uses an externally installed JRE as its embedded JVM?
3. If the answer to 2. above is 'yes', Is it possible to use any version of JVM as the embedded JVM? ( Or is there a compatibility matrix for each Oracle version )
4. Is it possible to have multiple embedded JVMs ( one for each Java version ) and to let the code decide which JVM it should run on? ( I saw a switch -edition for loadjava, but it was not clear what it was meant for )

Even partial answers would be much appreciated

Answer 1

1. No
2. No
3. No
4. No

The embedded JVM is (slightly) customized from a normal JVM and is compiled as part of the database. Different versions of Oracle have a different internal JVM so you could upgrade the JVM version by upgrading the database. If you upgrade to 12.1 or later you would be able to choose between two different JVMs though it is an either/ or choice-- you can't have some code using one JVM and some using another.

A Java stored procedure can't use an external JVM.