It seems that there is bug in DefaultValue for Enum in Structures when adding new fields.

Initially we have:

[HierarchyRoot]
[Serializable]
public class Book : Entity
{
    [Field, Key]
    public int Id { get; private set; }

    [Field]
    public string Title { get; set; }
}

Now creating:

new Book() { Title = "Alfabet" };
new Book() { Title = "Second" };
new Book() { Title = "Blue" };

After that adding structure BookSettings to class Book:

[Serializable]
public class BookSettings: Structure
{
    [Field(DefaultValue = BookSize.Octavo)]
    public BookSize Size { get; set; }

    [Field(DefaultValue = 55)]
    public int Pages { get; set; }

}

public enum BookSize
{
    Folio = 0,
    Quarto = 1,
    Octavo = 2
}

[HierarchyRoot]
[Serializable]
public class Book : Entity
{
    [Field, Key]
    public int Id { get; private set; }

    [Field]
    public string Title { get; set; }

    [Field]
    public BookSettings BookSettings { get; set; }

}

Trying to perform and exception:

[InvalidOperationException: Literal type 'DomainModel.BookSize' is not supported.]
Xtensive.Sql.SqlValidator.EnsureLiteralTypeIsSupported(Type type) +102
Xtensive.Sql.SqlDml.Literal(Object value) +80
Xtensive.Storage.Providers.Sql.SqlActionTranslator.GetDefaultValueExpression(ColumnInfo columnInfo) +75
Xtensive.Storage.Providers.Sql.SqlActionTranslator.CreateColumn(ColumnInfo columnInfo, Table table) +438
Xtensive.Storage.Providers.Sql.SqlActionTranslator.VisitCreateColumnAction(CreateNodeAction createColumnAction) +196
Xtensive.Storage.Providers.Sql.SqlActionTranslator.VisitCreateAction(CreateNodeAction action) +193
Xtensive.Storage.Providers.Sql.SqlActionTranslator.VisitAction(NodeAction action) +282
Xtensive.Storage.Providers.Sql.SqlActionTranslator.VisitAction(NodeAction action) +183
Xtensive.Storage.Providers.Sql.SqlActionTranslator.VisitAction(NodeAction action) +183
Xtensive.Storage.Providers.Sql.SqlActionTranslator.VisitAction(NodeAction action) +183
Xtensive.Storage.Providers.Sql.SqlActionTranslator.VisitAction(NodeAction action) +183
Xtensive.Storage.Providers.Sql.SqlActionTranslator.VisitAction(NodeAction action) +183
Xtensive.Storage.Providers.Sql.SqlActionTranslator.VisitAction(NodeAction action) +183
Xtensive.Storage.Providers.Sql.SqlActionTranslator.Translate() +877
Xtensive.Storage.Providers.Sql.SchemaUpgradeHandler.UpgradeSchema(ActionSequence upgradeActions, StorageInfo sourceSchema, StorageInfo targetSchema) +982
Xtensive.Orm.Building.Builders.DomainBuilder.SynchronizeSchema(SchemaUpgradeMode schemaUpgradeMode) +2240
Xtensive.Orm.Building.Builders.DomainBuilder.BuildDomain(DomainConfiguration configuration, DomainBuilderConfiguration builderConfiguration) +594
Xtensive.Orm.Upgrade.UpgradingDomainBuilder.BuildStageDomain(UpgradeStage stage) +406
Xtensive.Orm.Upgrade.UpgradingDomainBuilder.Build(DomainConfiguration configuration) +436
Xtensive.Orm.Domain.Build(DomainConfiguration configuration) +31

We found:

• We get exception in case of adding Enum field to Structure with DefaultValue, but no matters, are there any records in database or not.

• When adding int field - everyting is ok.

• When adding Enum field to Entity (not Structure) everything is ok.

But there is one way to solve this: we can add Enum Field to Structure without DefaulValue. After that doing perform. And now we can add DefaultValue and it is successfully applied to the newly created entities.