Not that I can answer your question, as I do not use Windows, but I had to update some Oracle applications recently to be able to use 12.2 and up.

I noticed that the Oracle 11 client stuff works fine with Oracle 12.1 database server, but not with 12.2. I made the jump to Oracle Instant Client 18.3 and 19.3, and both work fine with the most recent stable DBI and DBD::Oracle in my environment (Linux, DBI-1.642, DBD::Oracle-1.80, perl-5.28.2)

I need to to know if it is possible to install more recent versions of DBI and DBD:Oracle using old Perl 5.16.3

I'm curious why you can't upgrade your Perl? 5.16.3 was released over 6 years ago, and since you're already on a "relatively modern" version of Perl, further upgrades shouldn't be all too difficult. Unless of course you've got modules that are only binary-compatible with 5.16.3 or something?

Minor edits shortly after posting.

I would gladly upgrade to a more recent Perl, but that may break some of the programs. We don't have the Perl programming expertise at our organization to handle that quickly - and we need to handle this quickly because our Win 2008 server contract ends 1/14/2020.

I would gladly upgrade to a more recent Perl, but that may break some of the programs.

Perl rarely breaks old code. That's why modern Perl needs use strict, use warnings, use feature - changed defaults would break old code.

We don't have the Perl programming expertise at our organization to handle that quickly - and we need to handle this quickly because our Win 2008 server contract ends 1/14/2020.

Roll out the changes (i.e. the new Perl version) to your test environment and check what breaks. No need for guessing and prejudices.

No test env? Time to clone your production env ASAP. Having a verified(!!!) backup of your production env also sounds like a good idea.

Alexander

--
Today I will gladly share my knowledge and experience, for there are no sweeter words than "I told you so". ;-)

The problem is that we have to upgrade to Win 2012 and Oracle 11g is not compatible - only 12.2 is.

I doubt that. Generally, Oracle clients and servers are compatible with a major version difference of at least 1, i.e. Client 11 and Server 12 or vice versa. A major version difference of 2 should still work. At least, it was so for decades. I remember using C8 with S10 and C9 with S11, also C11 with S10.

Alexander

I mean compatible with Win 2012. Oracle 12.1 and below are not. One of the major updates in Oracle 12R2 is Win 2012 compatibilty.