[Nepomuk] Virtuoso issues after upgrading

[Felix Tiede]

Hi.

I've had issues with Akonadi and Nepomuk, resulting in Akonadi not working 
due to "Nepomuk QueryServer not available".

Turned out, I had upgraded virtuoso from 6.00 to 6.10 w/o upgrading the 
database. There was also an old transaction log probably left over from an 
unclean virtuoso shutdown prior to upgrade.

This I found out by starting 'nepomukserver &' from a console and reading 
virtuoso's messages. Virtuoso shut itself down.

Solution of the problem contained two steps.
First I had to clean an old transaction log, which was incompatible with 
virtuoso-6.10. Officially one should install the old version of virtuoso, 
rollforward the transaction log, then shutdown and upgrade. For me this was 
not an option as my distribution does no longer provide a package for the 
old virtuoso version. So I just deleted the transaction log hoping it did 
not contain anything important.

Second was upgrading the database itself.
There is a howto for this here:
http://virtuoso.openlinksw.com/dataspace/dav/wiki/Main/UpgradingToVOS610#Upgrading%20to%20VOS%206.1.0%20from%20an%20earlier%20VOS%206.x

For Nepomuk it doesn't work, unless one gets hold of the temporary ini-File 
used to configure its virtuoso-instance. After starting virtuoso "by hand" 
with a copy of this file ($> virtuoso-t +config /path/to/file +foreground) I 
could connect to it by simply calling isql-v from another terminal.

Next thing: The file sqlrdf23.sql mentioned in the link does not exist in 
virtuoso's opensource filetree. Running out of options I just tried using 
libsrc/Wi/clrdf23.sql from the opensource tarball and that worked as 
described by the tutorial (took some time, then shut down the virtuoso 
instance).

Rerunning nepomukserver after these steps showed one remaining error:
The xpf extension function http://www.openlinksw.com/xsltext/:unixTime2ISO-
>DB.DBA.XML_UNIX_DATE_TO_ISO does not exist. Please delete the corresponding 
row from DB.DBA.SYS_XPF_EXTENSIONS and restart the server.

I don't know how to get rid of this error, but seemingly this doesn't 
prevent nepomuk from running nicely with virtuoso and Akonadi now reports a 
working search interface.

If there are any questions about this, don't hesitate to ask me.

Regards and keep up the good work :)
Felix