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Chapter 20: Policy Based Management
20
The last two pages are not without purpose. There may potentially be a large number of
conditions and policies; the dependent policies and conditions pages are useful for quickly
tracking down a condition or policy.It’s worth spending some time browsing the facets and exploring the properties of each
facet available from the facet context menu.The Object Explorer ➪ Management ➪ Policy Management ➪ Facets context menu also
includes New Condition and New Policy. The only difference between these context menu
items and New Condition under Conditions or New Policy under Policies is that when the
new condition or policy is opened from the facet node, it preselects the facet in the drop-
down selection box. This fact is worth noting because PBM is context-sensitive; meaning if
you were to try and evaluate a policy on an object from a context menu on a specifi c object,
such as a table, you will be presented only with the option to evaluate policies relating to
that particular facet.There’s not much action just looking at facets because their purpose is to be evaluated by
conditions. But you need to be intimately familiar with the breadth of facets and their
properties to realize the types of policies that may be declared and enforced by SQL Server.Because the facet collection is actually a many-to-many relationship between properties and
object types, it makes sense that there should be a way to see all the facets and properties
that apply to any given object. Indeed, every object in Object Explorer that can have PBM
applied has a Facet menu option in its context menu. Open the View Facets dialog (shown
in Figure 20-3) and it presents a drop-down box to select a facet from the list of facets that
applies to the object, and a list of applicable properties. If the object is an example of what
you want, the View Facets dialog can even export the current state to a new policy. Very cool.Conditions
Conditions are the second step in the chain and provide the logical connection between
facet properties and policies. Most of the key policy design decisions are made while creat-
ing conditions.To begin building a new condition, use either the Management ➪ Policy
Management ➪ Conditions context menu and choose New Condition or Object Explorer
Management ➪ Policy Management ➪ Facets ➪ Database context menu.You can open an existing condition by double-clicking the condition or by using the
Property command in its context menu. A condition may have multiple expressions, but
each condition is based on only one facet, so every property in all the expressions in a con-
dition must belong to the same facet.Condition expressions use facet properties in boolean expressions that can be evaluated as
true or false. The expression consists of a facet property, a comparison operator (such as
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