I create entity with field:

[Field(Precision = 38,Scale = 0)]
public decimal Number { get; set; }

and try to write this walue:

using (var transactionScope = Transaction.Open())
{
    var helloWorld = new MyEntity { Number = 1234567890123456789.0m };
    transactionScope.Complete();
}

it's ok, write with no errors, but when I try to read this entity:

foreach (var myEntity in Query.All<MyEntity>())
  Console.WriteLine(myEntity.Number);

I catch exception:

System.OverflowException was unhandled
  Message=Conversion overflows.
  Source=System.Data
  StackTrace:
       at System.Data.SqlTypes.SqlDecimal.ToDecimal()
       at Xtensive.Sql.SqlServer.v09.TypeMapper.ReadDecimal(DbDataReader reader, Int32 index)
       at Xtensive.Sql.ValueTypeMapping.TypeMapping.ReadValue(DbDataReader reader, Int32 index)
       at Xtensive.Storage.Providers.Sql.DbDataReaderAccessor.Read(DbDataReader source, Tuple target)
       at Xtensive.Storage.Providers.Sql.CommandProcessor.<RunTupleReader>d__0.MoveNext()
       at Xtensive.Storage.Providers.Sql.SessionHandler.<Xtensive.Storage.Providers.Sql.IQueryExecutor.ExecuteTupleReader>d__1.MoveNext()
       at Xtensive.Storage.Providers.Sql.SqlProvider.<OnEnumerate>d__0.MoveNext()
       at Xtensive.Storage.Rse.Providers.ExecutableProvider.<GetEnumerator>d__0.MoveNext()
       at System.Collections.Generic.List`1..ctor(IEnumerable`1 collection)
       at System.Linq.Enumerable.ToList[TSource](IEnumerable`1 source)
       at Xtensive.Storage.Rse.RecordSet.<GetEnumerator>d__4.MoveNext()
       at System.Linq.Enumerable.WhereSelectEnumerableIterator`2.MoveNext()
       at Xtensive.Core.EnumerableExtensions.<Batch>d__20`1.MoveNext()
       at Xtensive.Core.EnumerableExtensions.<ApplyBeforeAndAfter>d__28`1.MoveNext()
       at Xtensive.Storage.TransactionalExtensions.<ToTransactional>d__0`1.MoveNext()
       at System.Linq.Enumerable.<SelectManyIterator>d__14`2.MoveNext()
       at Project6.Program.Main(String[] args) in c:\users\klekovkin\documents\visual studio 2010\Projects\Project6\Project6\Program.cs:line 32
       at System.AppDomain._nExecuteAssembly(RuntimeAssembly assembly, String[] args)
       at Microsoft.VisualStudio.HostingProcess.HostProc.RunUsersAssembly()
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state, Boolean ignoreSyncCtx)
       at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
       at System.Threading.ThreadHelper.ThreadStart()
  InnerException: