Administration Guide › Set Up Views › How Views Work › How the DSA Processes Phases in a View

How the DSA Processes Phases in a View

A view contains one or more phases, which are numbered. When the view is invoked, the DSA goes through each phase in the view, in order, and runs the phase's search. The power of views arises because a phase can use, as input to its search, results from a previous phase in the view. The DSA runs a phase as soon as the phase has all the input it requires.

You can specify that the DSA should use the output of one phase as input in another phase. You do this using the views parameters, which you include in the view definition in place of attribute values. The DSA replaces parameters with values as soon as the results are available, either from the values given in the invoking search command, or from the result of a phase.

The DSA runs a phase as soon as all the parameters it needs have been replaced by values, and it runs phases in parallel if possible.

The order of the phases is important because the DSA runs each phase only once per view invocation, and the DSA can only replace a phase's parameters with the results from earlier (lower numbered) phases. That is, a phase's parameters cannot refer to later phases.