Constructing cross-database SQL

Constructing SQL that can run across multiple database vendor databases is a design goal for a lot of applications in the hope that their development investment can create better return on investment through streamlined porting and reducing maintenance. The goal of standards (whether SQLMM, OGC SFA or SQL92) is to facilitate the achievement of these design goals. The presentation of the SQL/MM geometry type hierarchy and function set in this chapter is to introduce the only foundation that exists to support cross-platform spatial SQL today. But, as we shall see, nothing is perfect.

Is database independence possible?

It is common to meet developers and architects who believe that the only sound approach to using a database is to aim for database independence. That is, that all application database logic must be implemented such that it can run on any database vendor's product.

As Thomas Kyte observed in his book, Effective Oracle by Design.

Many times, people approach...