Table extensions provide a way to add fields to a table without over-layering. This means that we don't need to perform a code merge when the base package is changed.
In this recipe, we will add a field to the SalesConfirmHeaderTmp table, which we will use in the How to customize a document layout without an over-layer recipe.
It is common to have the main development work in one package, and reports in a higher package, as this can help with deploying updates. When deciding which package this table extension should be done in, we need to consider the scope of its usage should be. If we create the additional fields in a reporting package, which references a main development package, the main development package will not be able to use this field.
Sometimes a report drives the requirement for additional fields. So, it can seem natural to add the new fields...