SqlProfileProvider persists profile properties in three fields of the aspnet_Profile table: PropertyNames, PropertyValuesString, and PropertyValuesBinary. The following is a synopsis of what's stored in each field:
* PropertyNames holds a string value containing information about the profile property values present in the PropertyValuesString and PropertyValuesBinary fields. The string holds a colon-delimited list of items; each item denotes one property value, and it is encoded in the following format:
Name:B|S:StartPos:Length
Name is the property value's name. The second parameter, which is either B (for "binary") or S (for "string"), indicates whether the corresponding property value is stored in the PropertyValuesString field (S) or the PropertyValuesBinary field (B). StartPos and Length indicate the starting position (0-based) of the corresponding property value within these fields, and the length of the data, respectively. A length of -1 indicates that the property is a reference type, and that its value is null.
* PropertyValuesString stores profile property values persisted as strings. This includes property values serialized by the .NET Framework's XML serializer, and property values serialized using string type converters. The "S" values in the PropertyNames field contain the offsets and lengths needed to decompose PropertyValuesString into individual property values.
* PropertyValuesBinary stores profile property values persisted in binary format—that is, profile properties that were serialized using the .NET Framework's binary serializer. The "B" values in the PropertyNames field contain the offsets and lengths needed to decompose PropertyValuesBinary into individual property values.
Note that profile providers are not required to persist data in this format or any other format. The format in which profile data is stored is left to the discretion of the person or persons writing the provider.
original link for more info :http://msdn.microsoft.com/en-us/library/aa478953.aspx
hope this helps.