Along with RDB (DEC's SQL DB implementation) and DBMS-32 (DEC's CODASYL implementation), the CDD ("Common Data Dictionary") was built on top of the KODA engine.

Along with RDB (DEC's SQL DB implementation) and DBMS-32 (DEC's CODASYL implementation), the CDD ("Common Data Dictionary") was built on top of the KODA engine. CDD wasn't really free with the operating system, but it was ubiquitous. I spent some time hacking on that too for the report wizard people. I concur, the notion of "an army marches on its data" was an intrinsic in those environments. It also extended to related technologies such as networking, messaging, lambdas (DECNet Network Objects), and [edit: distributed, cluster-wide] locking. Obviously there are echos of this in today's cloud and other tightly integrated offerings. You might not agree with the entirety of the vendor implementation, but there was undeniably one to disagree with. The report wizard people competed directly with Datatrieve, along with being bundled with for instance a large ERP package.