In the previous post, we defined a basic approach to selecting a pipeline data model. The important thing is to determine which model best fits the needs of your organization. In this post we examine the high-level characteristics of the PODS data model, and lay out some criteria for deciding whether PODS is a good fit for you.
PODS is fundamentally a relational data model, meaning that it is intended to be implemented on a Relational Database Management System (RDBMS) platform such as Oracle or Microsoft SQL Server. PODS is neutral with respect to Geographic Information System (GIS) technology by design. Although optimized for use with ESRI Linear Referencing technology, PODS can readily be implemented with a wide variety of GIS technologies, as shown below.
As a relational data model, PODS benefits from the strengths of RDBMS technology:
- Relational integrity is automatically enforced
- Data in the model can be readily accessed via Structured Query Language (SQL)
- RDBMS processing tools such as stored procedures can be used to manipulate the data
As its name implies, PODS is intended to be a data standard. This means that the content of the data model is rigorously defined and must be adhered to closely for compliance purposes. The upside of this approach is a rich data model with extensive content; the downside is lack of flexibility. The PODS data model essentially embodies a one-size-fits-all approach.
A potential weakness of PODS is that the mechanism for spatially enabling the model with a GIS is not specified; there is no one approved method for spatially enabling PODS. In practice this means that every PODS software vendor sells a proprietary solution for spatially enabling PODS. You’ll have to exercise considerable care if you choose to implement a vendor-supplied PODS solution because not all PODS software providers play nicely with others.
PODS might be a good fit for your organization if:
- Your company has deep expertise in a particular RDBMS technology
- Your company regards relational data integrity as being extremely important
- Your company regards access to and integration with data at the SQL level as important
- Your company views a standards-based data model as being important
- Your company makes use of several different computer mapping technologies
- Your company is not averse to potentially being locked into a single provider spatial solution, OR your company has sufficient expertise to spatially enable PODS on its own