CREATE TABLE [dbo].[map_root] (
    [id]		INT             IDENTITY (1, 1) PRIMARY KEY CLUSTERED NOT NULL, 

CREATE TABLE [dbo].[map_root] (
    [id]		INT             IDENTITY (1, 1) NOT NULL,    
    [host]		VARCHAR (255)   NOT NULL,
    [hash]		VARCHAR (255)   NOT NULL,
    [created]	DATETIME NULL	DEFAULT(GETDATE()),
    CONSTRAINT [PK_map_root] PRIMARY KEY CLUSTERED 
    (
        [id] ASC
    ),
    CONSTRAINT [UQ_map_root] UNIQUE NONCLUSTERED
    (
        [host], [hash]
    )
);

alter table dbo.Records drop constraint [UQ_Records_CreateDate];
go
alter table dbo.Records add constraint [UQ_Records_CreateDate_SomeFieldId] unique (CreateDate, SomeFieldId);
go

  [created]	DATETIME NOT NULL	DEFAULT(GETDATE()),