Data Types in Analysis Services
For all DataItem objects, Analysis Services supports the following subset of System.Data.OleDb.OleDbType. To set or read the data type, use DataItem Data Type (ASSL).
Supported Data Types
BigInt 
A 64bit signed integer. The BigInt value type represents integers with values ranging from negative 9,223,372,036,854,775,808 to positive 9,223,372,036,854,775,807. 
Binary 
A stream of binary data of Byte type. Byte is a value type that represents unsigned integers with values that range from 0 to 255. 
Boolean 
Instances of this type have values of either true or false. 
Currency 
A currency value ranging from 922,337,203,685,477.5808 to +922,337,203,685,477.5807 with accuracy to a tenthousandth of a currency unit (four decimal places). 
Date 
Date and time data, stored as a double. The whole portion is the number of days since December 30, 1899, and the fractional portion is a fraction of a day or time of the day. 
Double 
A floatingpoint number within the range of 1.79769313486232E +308 to 1.79769313486232E +308. A Double value stores number information up to 15 decimal digits of precision. 
Integer 
A 32bit signed integer that represents signed integers with values that range from negative 2,147,483,648 through positive 2,147,483,647. 
Single 
A floatingpoint number within the range of  3.4028235E +38 through 3.4028235E +38. A Single value stores number information up to 7 decimal digits of precision. 
Smallint 
A 16bit signed integer. The Smallint value type represents signed integers with values ranging from negative 32768 to positive 32767. 
Tinyint 
An 8bit signed integer. The Tinyint value type represents integers with values ranging from negative 128 to positive 127. 
UnsignedBigInt 
A 64bit unsigned integer. The UnsignedBigInt value type represents unsigned integers with values ranging from 0 to 18,446,744,073,709,551,615. 
UnsignedInt 
A 32bit unsigned integer. The UnsignedInt value type represents unsigned integers with values ranging from 0 to 4,294,967,295. 
UnsignedSmallInt 
A 16bit unsigned integer. The UnsignedSmallInt value type represents unsigned integers with values ranging from 0 to 65535. 
UnsignedTinyInt 
An 8bit unsigned integer. The UnsignedTinyInt value type represents unsigned integers with values that range from 0 to 255 
WChar 
A nullterminated stream of Unicode characters. A WChar is a sequential collection of Unicode characters that is used to represent text. 
AMO Validations on Data Types
The following table lists the extra validations that Analysis Management Objects (AMO) does for certain bindings:
Object 
Binding 
Allowed Data Types 

DimensionAttribute 
KeyColumns 
All but Binary 
NameColumn 
Only WChar 

SkippedLevelsColumn 
Only integer types: BigInt, Integer, SmallInt, TinyInt, UnsignedBigInt, UnsignedInt, UnsignedSmallInt, UnsignedTinyInt 

CustomRollupColumn 
Only WChar 

CustomRollupPropertiesColumn 
Only WChar 

UnaryOperatorColumn 
Only WChar 

ValueColumn 
All 

AttributeTranslation 
CaptionColumn 
Only WChar 
ScalarMiningStructureColumn 
KeyColumns 
All but Binary 
NameColumn 
Only WChar 

TableMiningStructureColumn 
ForeignKeyColumns 
All but Binary 
MeasureGroupAttribute 
KeyColumns 
All but Binary 
Distinct Count Measure 
Source 
BigInt, Currency, Double, Integer, Single, SmallInt, TinyInt, UnsignedBigInt, UnsignedInt, UnsignedSmallInt, UnsignedTinyInt 