Special characters show junk in CLOB columns after upgrade to Oracle 12.2.0.1 with JDBC

Thanks to my support colleague Roland Graeff who told me about this issue at a customer today. And I consider this a pretty serious issue. It can happen that Special characters show junk in CLOB columns after upgrade to Oracle 12.2.0.1. with JDBC. This is as bad as it sounds. Roland told me about a case where the application showed weird characters instead of German umlauts (ä, ö, ü, Ä, Ö, Ü) after an upgrade from Oracle Database 12.1.0.2 to 12.2.0.1. Special characters show junk in CLOB columns after upgrade to Oracle 12.2.0.1 with JDBC Roland explained to me that…

How to patch the Oracle Instant Client?

That’s an interesting question a customer raised the other day: How to patch the Oracle Instant Client? I silently assumed that there’s a new release of the Oracle Instant Client every quarter or at least when we deliver fixes which apply to the client as well. Hm … What is the Oracle Instant Client? First of all, the Oracle Instant Client is a pretty cool thing. It gets distributed via OTN as a simple download. You deploy it to your client machine, you set LD_LIBRARY_PATH (or PATH on Windows) and add a tnsnames file if necessary, you may add SQL*Plus…

Client Certification for Oracle Database 12.1.0.2/12.2.0.1

I’ve received a question about client certification for Oracle Database 12.2.0.1 the other day. And this reminded me on this very helpful MOS Note: MOS Note: 207303.1 Client / Server Interoperability Support Matrix for Different Oracle Versions  It spans the client interoperability back to the Oracle 9.2 days and is a very helpful resource. And don’t forget that sometimes client software may need a patch as well. A customer I exchange emails with on a regular basis just upgraded the Database server to Oracle Database 12.1.0.2 and saw several strange errors with the JDBC client despite the fact that they…