2.0.5 housekeeper with oracle is always 100% busy - days+ ! and newer drops back to 0%
Small part of housekeeper strace with 2.0.5 you can see here http://pastebin.com/9tERRGUE

After one week with 2.0.5 I downgraded to 2.0.4 and it solved the problem immediately.

Last day housekeeper deletes 4 times more records as usually (there is special code for this).

Today morning I tried 2.0.5 sources BUT without changes from ZBX-5920 (thanks dimir for preparing tar.gz)
And housekeeper is working as it should !

So I suppose the ZBX-5920 introduced some side effect for housekeeper on Oracle.