What are the TT_DB directories, and what is the difference between the types database and the TT_DB directories?

The ToolTalk types databases store the static ptype and otype definitions. These definitions declare the messages to which applications and objects respond. The ToolTalk types compiler modifies the types database when you add or change static type definitions. Upon starting, ttsession reads in these type files.

The TT_DB database is created by rpc.ttdbserverd. The tt_db directories contain the associations between files in this partition and the sessions with patterns interested in these files. It also contains all the object spec information for files in this partition.