6.6.3. Resource Set OR Logic

The unordered set logic discussed so far has all been "AND" logic. To illustrate this take the 3 resource set figure in the previous section. Those sets can be expressed, (A and B) then (C) then (D) then (E and F).

Say for example we want to change the first set, (A and B), to use "OR" logic so the sets look like this: (A or B) then (C) then (D) then (E and F). This functionality can be achieved through the use of the require-all option. This option defaults to TRUE which is why the "AND" logic is used by default. Setting require-all=false means only one resource in the set needs to be started before continuing on to the next set.

Example 6.13. Resource Set "OR" logic: Three ordered sets, where the first set is internally unordered with "OR" logic

<constraints>
    <rsc_order id="order-1">
      <resource_set id="ordered-set-1" sequential="false" require-all="false">
        <resource_ref id="A"/>
        <resource_ref id="B"/>
      </resource_set>
      <resource_set id="ordered-set-2" sequential="true">
        <resource_ref id="C"/>
        <resource_ref id="D"/>
      </resource_set>
      <resource_set id="ordered-set-3" sequential="false">
        <resource_ref id="E"/>
        <resource_ref id="F"/>
      </resource_set>
    </rsc_order>
</constraints>

Important

An ordered set with require-all=false makes sense only in conjunction with sequential=false. Think of it like this: sequential=false modifies the set to be an unordered set using "AND" logic by default, and adding require-all=false flips the unordered set’s "AND" logic to "OR" logic.