History tracking in Contributor

[EP_explorer]

When I choose item 'Full debug information with data' from dropping out list 'History tracking' which situated in Contributor Administration Console -> Application->Development->Web-Client Configuration->Application Options I know that changes in Contributor Application are appeared in table 'History' in database on which Contributor Application based.

But I don't know how I can work with this table. For example I see column 'userguid' but I don't know where I can find name of user which fit this 'userguid' for version higher 8.2 (I know for version 7 that I should publish application in View Layout and find necessary information - list of users in table 'annotationuser' and I have heard the information about Users in 8.2 and higher versions consisted in one table of application but I didn't know in which). Also I don't know how I can understand content of column 'dataxml'.

Can somebody prompt where I can find description of this table? Or may be somebody knows where I can look for user name fit to 'userguid' and how I can understand contention of 'dataxml' (may be special viewers exist).