How to synchronize a java method called by PL/SQL

Question

I just have a problem relative to concurrency whose logic flow is when a client (called Oracle Forms) will submit a request （called concurrent program ) and call a plsql procedu

Answer 1

I have no idea how the JVM inside the Oracle DB is implemented, but since (at least in some common configurations) every database connection gets its own server process, then if a separate JVM is embedded into each of those, a synchronized block won't do you much good. You'd need to use database locks.

Answer 2

1. Assuming that the calls to the Java static method are done within the same classloader, then synchronized is all you need.

2. Your logging may be faulty. How exactly are you logging?

3. Your statement about the database lookup being "time consuming" is not convincing. Databases tend to cache data, for example.

In a nutshell: if, by your definition, an "atomic operation" is a combination of lookup + insert, then you should "synchronize" over both. Acquiring a database lock seems like a reasonable way to go about it.