Sorry, I should have pointed out that I have MySQL running on both nodes, with the Standby node replicating the Master node. This means that both nodes will be the same until the Master fails (I am disconnecting it from the network), after which any changes made through FactoryPMI are made to the Standby database.
I know that reconnecting the Master will then require the MySQL databases to be brought back into synch manually, but I noticed that data stored in other (non-SQLtags) tables is displayed from the Master, while SQLTags values (DB tags at any rate) stay at the Standby values until they are changed.