The RowType and RowTypeName properties are linked. Therefore, setting the RowType changes the RowTypeName to value of PgSqlRowType.Name property. When you set RowTypeName property, RowType becomes a null reference (Nothing in Visual Basic).
The RowType property can be used when you provide data as string and want to have it parsed as certain composite type. The other way to pass a PgSqlRow as parameter value is to assign a PgSqlRow object directly to Devart.Common.DbParameterBase.Value property.
Target Platforms: Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2