Creating a Primary Composite Key for DM Output Table

Tick all the keys you want in your primary key. Do not tick the index button against each column since this creates single indicies and will SLOW up the load.

Instead tick the Index box next to the Index Options.

If you open the index properties (right) then ensure you untick the suppress error when you are developing otherwise the index creation will fail without warning.

The index is not actually a primary key but a unique index since a primary key requires all non nullable columns.