>> Adriano, define please goals, problems and only after - possible solutions.
>> Else we never understand each other
> 1) We are a database or FTP server?

You should know ;)

> 2) We are defining a public plugin interface or something only the FB
> project may use and can change in each version?

I see no relation between this question and subject of discussion.

> 3) Should it be harder to use or easy?

I prefer easy ;)

> Vlad, if official Java plugin allows only to execute classes that user
> should invent a way to put in the server, it will certainly not be very
> usable.

Why ? Why Java classes is better than current UDF's ? It is safe ?
Really ? Or sysadmin (not dba !) must configure Java on his computer
first to make is safe ? And made it not usable at the same time if classes
want to do something forbidden ;)

Correct me where i'm wrong :

I'm ISP\sysadmin. I'm allow you (dba) to run your database on my
computer. I configure JVM and disallow any Java code to write into FS.
You (dba) can't configure JVM instance hosted by database engine to do
something i'm not allow. I (ISP) don't want to approve any of your UDF's
independent on which language you write it. I (ISP) don't trust you (dba)
to configure security on my machine. All i can allow you to do is to run
database engine which is more or less trusted to me.

> Possible good Java plugin would allow to upload
> JAR/class/resources/sources, or write inline Java code that will be
> compiled in the server.
>
> What you're suggesting (a global permission to define external
> procedures)

This is widely approved practivce, i believe, - every action must have
corresponding permission. EXECUTE, CREATE, DECLARE, etc - every

> doesn't make sense because:
>
> 1) If well configured, Java code is safe as PSQL

I (ISP) don't trust you (dba). Remember it ;) Hence there is no sence
to configure Java security through database. But it is still required to allow\
disallow users to execute procedures. Independent of language. And this is
required by dba, not ISP.

> 2) No matter how good configured, binary machine code is not safe - I
> see no comments from you about "security by obscurity" that I told

Because it's not "security by obscurity". Nobody can override FS
permissions. And if you don't know allowed directory - you can't write
anything anywhere.

Again, please, define goals and problems. Imagine i know nothing
about Java, JMV, Java security etc...

Regards,
Vlad