Australian spatial data, in my opinion, is very confusing. According to The Australian Statistical Geography Standard (ASGS), our spatial structure is split into 2 groups: the ABS Structures and the non-ABS Structures.
As you can see above, ABS and Non-ABS structures do not always overlap. From my own observation, I think that most of the Australia-related datasets normally use postcode/suburbs as the spatial structure. But keep in that in Australia, postcode and suburb do not always align. Some postcodes can have multiple suburbs. Furthermore, there are postcodes that can span across the state borders, for example:
Postal Area Postal Areas that cross state or territory borders POA 0872 Postal Area 0872 crosses into NT, SA and WA POA 2540 Postal Area 2540 crosses NSW and OT (Jervis Bay) POA 2618 Postal Area 2618 crosses NSW and ACT POA 2620 Postal Area 2620 crosses NSW and ACT POA 3585 Postal Area 3585 crosses Vic. and NSW POA 3644 Postal Area 3644 crosses Vic. and NSW POA 4383 Postal Area 4383 crosses Qld and NSW POA 4825 Postal Area 4825 crosses Qld and NT
Working with postcode and suburbs can be tricky. Postcode boundaries are approximations. What we can do is to use the POS_Shapefile from the ABS to make it more accurate. Furthermore, suburb boundaries aren’t available from Tableau. If you use Postcode boundaries with suburbs’ names, you will notice some of the suburbs are missing. The reason being that one postcode can have multiple suburbs. Similarly, you can use SSC_Shapefile from the ABS in Tableau to have better representations.
In conclusion, if the dataset used postcode as their locality, we can just go ahead and use the postcode as the geometry input to Tableau. But, if they used suburbs as the representation, we shouldn’t or even wouldn’t use postcodes as the geometry input in Tableau. Your analysis will be telling lies and present inaccurate information to viewers. Even worse, it can cause financial loss to your business or clients. Try to be vigilant and cautious when dealing with Australian spatial data in Tableau.