I’ve already covered how to create a multivalue table for SQL MAs; and I’ve also talked about generating Delta tables for single-valued attributes. If you are doing multivalue imports from SQL you are really going to want to get Delta imports working there too …. those babies can be sllloooowww. We need two tables for multivalue imports, which I am referring to as the Objects and the Values tables. The thing to understand is that the Delta table is based the Objects table only. You tell MIIS which lines have changed in the Objects table, but you still give it the entire Values table for cross-referencing.
When creating the Delta table follow the same method as explained before – create a table with the same design as the Objects table, and then add an extra “ChangeType” column, which will contain ‘Add’, ‘Delete’ or ‘Modify’.
If you’re only importing one multivalued attribute, or if you don’t have a lot of data, you can stop here. Chances are that you have a number though, or you have combined multi- and single-valued attributes in one table, and for that you’re going to need Attribute-level imports.