Historian database shows ? on a few tagnames.

Hi Richard,

I queried this behavior against AVEVA's case database, and was only able to find one case which lists the following:

After exporting the Manual Tags from SMC into a text file, noticed some Tagnames are prefix with question mark (i.e ?A6E_AT_L3_07_001.PV ). Using Historian Client Trend, these tagnames appeared normal in TagPicker, and able to Trend it's logged values. Using Historian Client Query, the tagnames appeared normal in TagPicker, but when selected to view it's History Values, query failed. Noticed there are some 'empty spacing' in the tagname when select the SQL tab to view the query. Removing these spaces, query can be performed successfully.

The case then also mentions a dev investigation as well as a hotfix. I am unable to view either of these, so I could not tell you if these would actually aid in your situation. Exact Hotfix: L00155400 for Historian 2017 U2

So, I would check to see if your problem tags can be queried within the Historian Client Query tool, and if not, see to what effect the actual SQL query may be failing. If you are unable to view a resolution there, or if the queries succeed, I would recommend contacting Tech Support for more information about that Hotfix, or other possibilities. 

Adam, thank you for that.  I'll try what you say (won't be until next week), and get a look at that hotfix.

Hi,

We’ve got the same symptoms on several galaxies. Could be due to either regional settings issues and sql collation.

You’ll have to rename the tags with ‘?’ by something without with the help of the aahtagrename utility https://knowledge.insourcess.com/?title=Operational_Efficiency%2FHistorian%2FMaximize_%26_Optimize%2FTN_Hist235_Historian_Tagname_Rename_Utility

To see all the impacted tag query the sql dbo.tag table and search for a space ascii character in the tagname.

Loris Carboni Thanks.  I'll try the rename utility (not for a week or more).

I looked at the rename utility, required stopping and disabling historian.  Users don't want to do that, so have made a support case,

Richard,

not sure there are other possibilities than this. If you have system platform or remote ideas working in store and forward mode then you might have more chance to stop historian because no data will be lost