The Physical Data Model - Microsoft SQL Server 2008 Analysis Services - page 351

parent, its DataID is the same as the DataID of the previously deleted member because
DataID is an ordinal of the record that contains the key. This can cause some confusion,
so you should try to avoid restoring deleted members when possible.

There is no way to remove records of deleted members from the store. If the application
deletes and adds a large number of unique members, the size of the attribute can grow,
even when there aren't many valid members in the attribute. The only way to get rid of
all the deleted members is to fully reprocess the dimension, which requires you to
reprocess all the cubes that use this dimension (if the dimension is a regular dimension
and not indirect—referenced or many-to-many). For more information about indirect
dimensions, see Chapter 8, “Advanced Modeling.”

Unary Operator Store
A member can have unary operators associated with it. For more information about unary
operators, see Chapter 13, “Dimension-Based MDX Calculations.” If an attribute can be
aggregated using unary operator expressions, it has a separate data structure, called a
unary operator store. A unary operator store is a bit store that contains information for
each member of the attribute indicating whether a member has a unary operator associ-
ated with it. A file with the .ustore extension contains the data for this store.

The information stored in the unary operator store is separated from other properties to
improve calculation performance. The designers of Analysis Services made this decision in
the hope that the content of this store would remain small, and would therefore always be
loaded into memory. The unary operator store doesn't keep the values of unary operators,
which are stored in the property store.

BLOB Store
Analysis Services supports a special kind of member property, named Value . You can set
the value of this member property to be the same as the key of the member, or you can
base it on data stored in a different column of the source table. This member property is
often used to associate columns that have the binary large object (BLOB) data type with
the member. BLOB columns are typically used to contain video files, pictures, sound files,
and other large binary objects. Because this data is large and rarely used, BLOB data is
stored in a separate store so that the sheer volume of this kind of data doesn't interfere
with other work. Analysis Services encodes and stores BLOB data as a string.

The following files support the BLOB store, in which <attribute ID> represents the iden-
tifier of the attribute:
. A main store file that holds 4-byte offset references to the string store, named

<attribute ID>.bstore

. A string store file that contains the string representations of the BLOB values, named

<attribute ID>.bsstore

Attribute Relationships

A dimension contains not only attributes, but also relationships between the attributes.
For more information about attribute relationships, see Chapter 5. For each member of the
attribute, it is important to identify and map the relationships between the member and