Re: trigger or listener?

Glenn Holmer wrote:
> a) DB trigger on the '400 that wakes up when the record is changed and 
> calls a Java program (also on the '400), passing the needed parameters 
> as arguments to main(); the Java program uses JDBC to update the 
> Postgres database on the Linux server.  Pro: probably easy to set up, 
> Con: new process spawned for each write.

IIRC: The DB trigger runs in the job that causes the trigger to fire, so
a new process is not created.

To make this process light-weight ... you could have the trigger send
some basic information to a dataqueue ... and then have your java
program watch the dataqueue.

> b) A Java program that runs all the time and listens for changes on the 
> AS/400 database using something like FileListener from the JT400 
> toolbox (haven't researched this yet); he would do the same as a).  
> Pro: single program, Con: don't know if it's possible.

FileListener events fire when an operation occurs to the FILE, not a
record in the file.  Although you might be able to use watch for
FileEvent.FILE_MODIFIED type events, I'm not sure that will give you the
information you are looking for (FILE_MODIFIED may only be indicated
when the file object is changed, not when a record is modified).  Mind
you, I've never played with this, so I'm not sure about anything.

david