Alexander Shkarlatov

Related #363 #337 #322

You can see how this is done in [cygwin ](https://www.cygwin.com/cgit/newlib-cygwin/tree/winsup/cygwin/fork.cc?id=25e40ae6aa4b51f08c60bab3d11bb28a9efc2847) and [mingw](https://github.com/msys2/msys2-runtime/blob/msys2-3.4.10/winsup/cygwin/fork.cc#L555)

There are 2 things that prevent us from using the code first: 1. ef6 tries to create a table with a column xmin 2. xmin is uint My decision: 1....

I agree that the list is better. About types : if define prop with type uint or long its don't work. I get exception about can't cast uint32 to int64...

About system column: if you make an attribute and convention ```csharp public class SystemColumnConvention : Convention { public SystemColumnConvention() { this.Properties() .Where(x => x.GetCustomAttributes(false).OfType().Any()) .Configure( c => c.HasColumnName(c.ClrPropertyInfo.GetCustomAttribute().Value).HasColumnAnnotation("SystemColumn",string.Empty).HasDatabaseGeneratedOption(DatabaseGeneratedOption.Computed)); } }...

I don `t know why developers do not exclude system columns when creating a database or migrating. I just find a workaround. Problem in [this class](https://github.com/danzel/Npgsql/blob/master/Npgsql.EntityFramework/NpgsqlMigrationSqlGenerator.cs). Need review for exclude...

**OFFTOP** maybe you can help me: how do I force EF to generate "default" in requests for updates and insertions? Example for what it is needed: ```sql create table Item...