Building Basic Dimensions and Cubes - Expert Cube Development with SSAS Multidimensional Models - page 47

Analysis Services will display the key of the member as its name. For
attributes with a very large number of members, you should always try
to use a column of the smallest possible numeric data type as the key to
an attribute and set the name separately. Using strings as keys can have a
performance overhead, as can using composite keys (that is, when you use
more than one column in the KeyColumns collection).

• AttributeHierarchyEnabled : This property controls whether a hierarchy

is built for this attribute, that is, whether the user can actually see this
attribute when they browse the cube and use it in their queries. By default,
it is True . If you set it to False , the attribute still exists, but is only visible in
the dimension as a property of another attribute. A good example of when
you would do this would be if you were building a Customer dimension.
You'd never want to be able to see a hierarchy containing phone numbers
and e-mail addresses. However, if you were looking at a specific customer, it
might be good to see this information as a property of that customer. Setting
this property to False also has the benefit of reducing the amount of time
needed to process the dimension.

• AttributeHierarchyOptimizedState : For attributes that have their

AttributeHierarchyEnabled property set to True , this property controls
whether indexes are built for the resulting attribute hierarchy. Setting this
property to False can improve dimension processing times, since building
an index for an attribute can take some time. However, the penalty you pay
in terms of query performance can be quite significant, so you should only
consider setting this to False for attributes that are rarely used in queries and
that are large enough to have an impact on dimension processing times.

• OrderBy , OrderByAttribute : The order in which members appear in an

attribute hierarchy can be important. For example, you would expect days
of the week to appear in the order of Sunday, Monday, Tuesday, and so
on rather than in alphabetical order. The OrderBy attribute allows you to
order the members on an attribute either alphabetically by name, by the
value of the key of the attribute, by the value of the name, or by the key of
another attribute that has a relationship with the attribute being ordered
(which attribute is used is controlled by the value of the OrderByAttribute
property). It is only possible to sort in an ascending order. As a result, you
may end up creating new numeric columns in your dimension table to use as
the key of an attribute in order to ensure the type of sorting you want.

• AttributeHierarchyOrdered : In some situations, where the order of

members on a very large attribute hierarchy doesn't matter much, disabling
sorting by setting the AttributeHierarchyOrdered property to False can
save a significant amount of time during dimension processing. This is shown
in the following blog entry: http://tinyurl.com/attributeordered .