The exact meaning of these prefixes is internal to product. If you can raise a support ticket we can ask engineering for it.
ODB - relates to errors that happen at the ODBC layer or exceptions caught at ODBC. It is a higher level exception wrapper over an underlying WDB error.
WDB - Errors that happened at the database layer. Something originating from database. The error is logged and then a higher level exception is thrown to report at the ODBC layer which is then logged as ODB-
XTK - Errors raised because of a schema. Like Amit said, one the errors you provided was raised when access was not available to user on the linked resource i.e. schema. Similarly, if there is a column missing you might get an error
Attribute 'registrationToken' unknown (see definition of schema 'Batch events (nms:batchEvent)'). XTK-170036 Unable to parse expression '[@registrationToken]'.
RED - These errors are associated with the redirection server or better to say with your tracking instance.
Thanks both, I wish I could mark both as correct answers.
XTK-170019 Access denied. (iRc=-69)
I performed an upgrade recently on one of our environment and noted the error above kept popping up in the web.log, I tried to reproduce it in staging by changing passwords on the sql account but realized that odb and wdb errors were logged instead, hence I knew it had nothing to do with database credentials but rather some other sort of access.