Dimensions in the Conceptual Model - Microsoft SQL Server 2008 Analysis Services - page 49

<TableID>dbo_customer</TableID>
<ColumnID>city</ColumnID>
</Source>
</KeyColumn>
<KeyColumn>
<DataType>WChar</DataType>
<DataSize>50</DataSize>
<Source>
<TableID>dbo_customer</TableID>
<ColumnID>state_province</ColumnID>
</Source>
</KeyColumn>
</KeyColumns>
Attribute Member Names
An attribute member's identifier is its name. The attribute member name is used pretty
much where you want to reference a specific attribute member. The name of the attribute
member can be either unique inside of the attribute or not. However, if the name is
unique within an attribute, Analysis Services can support it more efficiently. You can use a
property such as the MemberNameUnique . Otherwise, the property will come from the key.
The MemberNameUnique property is uniqueness of the attribute members' names, Analysis
Services uses the names of members to generate the member unique name; otherwise, it
uses member keys.
We use the DataItem object to specify the attribute member name. Unlike the data type
for the key, the data type for the member name can only be text or a format that can be
converted to text.
When you define a member name, avoid using spaces and special characters; they compli-
cate the use of member names. It's a good idea to avoid long names, too, because they
take more resources to store and retrieve and can therefore decrease system performance.
Storing the attribute member names can require gigabytes of disk space. Loading the
names into memory can be the main cause of a slowdown.
Collation is important part of the member name specification. The collation of a name
can change whether the name is unique or not. For example, suppose you have some
name that uses capital letters whereas another, similar name uses lowercase letters (for
instance, DeForge and Deforge). Depending on the Collation property value, the system
might treat these similar names as either different or the same, resulting in confusion and
unpredictable results for the user.
In addition, Collation affects the order the members will be sorted in. Sorting is an impor-
tant aspect of how attribute members are used in the system. Defining the right ordering
scheme is not always a simple task. For example, months in the year are usually not sorted
by name; it's typical to sort months by the numbers that indicate their place in the year.