PRECEDES follows FOLLOWS

Thanks for a tip-off from volleyball coach / Oracle guru Connor McDonald (and later by colleague Chris Muir), it seems 11gR2 was released while I was 30000ft in the sky.

I wouldn't be practising what I preach if I didn't point you to one of the best books in the online Oracle Documentation - the New Features Guide.

If you want to keep up with Oracle Technology, and learn a thing or two, every time a new version of Oracle is release, I highly recommend a peruse through this book.

Keep a lookout in the blog community because plenty of articles pop-up around these times showing off the shiny new features. One feature I'll mention today is an extension to triggers.

In a recent presentation I included some thoughts on compound triggers and a quick note on the FOLLOWS clause, allowing you to indicate that a trigger fire after a specified trigger.

This can be useful if you need to extend proprietary Oracle software.

create or replace trigger package_trigger
after update of salary
on employees
for each row
begin
dbms_output.put_line('package_trigger');
end old_way;
/

create or replace trigger custom_stuff
after update of salary
on employees
for each row
follows package_trigger
begin
dbms_output.put_line('custom_stuff');
end old_way;
/

I don't know whether it was an afterthought or this was just one of the last features installed in 11gR1 at the pleading request of a client, but it was a little odd that a PRECEDES type functionality wasn't included.

However now in 11gR2, this is now available.

There are caveats however, and in this case PRECEDES may only be applied to a reverse cross edition trigger - this is also a whole new ball game and I can't yet confidently tell you more about editions, except that Connor's been excited about the prospect of these for quite some time & it's impact throughout the database seems widespread.

Other features for the handy developer to keep an eye out for include:

• Enhancements to the Forms->Apex conversion process
• Analytical function improvements
• Recursive WITH clause - ANSI compliant hierarchical queries
• Flashback support for DDL
• Improvements to Oracle Scheduler

Oracle keeps on Oracling.