Restrictions on the Use of Datatypes
The PostgreSQL database places restrictions on the use of certain datatypes. Where possible, the DB Interface Module is flexible about datatypes. However, there are some situations where conversions are not possible. In these cases your applications must be aware of the contexts in which certain datatypes can be used. Table 3 outlines the known restrictions associated with each DB Interface Module type.
Table 3 – Restrictions on the use of DB Interface Module datatypes 
RWDBValue::ValueType
Restrictions
Blob
No restrictions
Char
UnsignedChar
No restrictions
Date
Only the PostgreSQL DateStyle ISO, MDY is supported.
DateTime
RWDateTime is limited to milliseconds, but PostgreSQL can support a much finer precision. PostgreSQL's timestamp type supports a range from 4713 BC to 5874897 AD. However, RWDateTime is limited to a datetime range of 09-14-1752 00:00:00.000 to 9999-12-31 23:59:59.999
Only the PostgreSQL DateStyle ISO 8601 format in MDY mode is supported.
TimeTuple
Only the PostgreSQL DateStyle ISO 8601 format in MDY mode is supported.
TimeTupleOffset
This datatype is not supported.
Decimal
No restrictions
Double
No restrictions
Duration
No restrictions
Float
No restrictions
Int
UnsignedInt
No restrictions
Long
UnsignedLong
No restrictions
MBString
This datatype is not supported.
LongLong
UnsignedLongLong
No restrictions
LongDouble
No restrictions
String
No restrictions
Short
UnsignedShort
No restrictions
WString
This datatype is not supported.
UString
This datatype is not supported.