Sending index hints to the SQL server from AX has been around for a long time and often it has not done any good since the SQL server is pretty good at picking the best way it self.
So when it ended up as a parameter in the AOS server configuration in AX 2009 and then removed from the configuration in AX 2012 we seemed clear from the trouble it could cause. Microsoft stated that it was deprecated with AX 2012 and no longer available …
So it seemed a bit strange that the SQL server apparently received the information on a server I was working on recently.
While going through about all possible stuff to locate why it was acting like the non-existing index hint flag was enabled, I was going through the registration database to compare it against an AOS we knew was working as expected. And there it was … the registration key called “hint”.
I did a bit of research and I was not the only one struggling with this. As it appears there are these values to choose from :
Empty = Index hints are enabled and LTRIM (yes, it is there too) is disabled.
0 = Both index hints and LTRIM are disabled. This has to be the recommended setting.
1 = The same as empty. Does that make sense? No, not really. Anyways …
2 = Index hints are disabled and LTRIM is enabled.
3 = Both index hints AND LTRIM are enabled
And just for refreshing the memory: The location of the registration keys are
and in here find the right AOS and configuration.