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Unique row constraint in SQL Server

I have the following table

CREATE TABLE [dbo].[LogFiles_Warehouse](
    [id] [int] IDENTITY(1,1) NOT NULL,
    [timestamp] [datetime] NOT NULL,
    [clientNr] [int] NOT NULL,
    [server] [nvarchar](150) COLLATE Latin1_General_CI_AS NOT NULL,
    [storeNr] [int] NOT NULL,
    [account] [nvarchar](50) COLLATE Latin1_General_CI_AS NOT NULL,
    [software] [nvarchar](300) COLLATE Latin1_General_CI_AS NOT NULL,
 CONSTRAINT [PK_Astoria_LogFiles_Warehouse] PRIMARY KEY CLUSTERED 
(
    [id] ASC
)WITH (PAD_INDEX  = OFF, IGNORE_DUP_KEY = OFF) ON [PRIMARY]
) ON [PRIMARY]

And I want to avoid duplicating rows in my table. I was thinking of creating a UNIQUE index in a complete table, but then SQL Manager Studio tells me that this is not possible because the key will be too large.

Is there any other way that I could apply unique rows across all columns except indexes?

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2 answers

Create an index UNIQUEfor hashed values:

CREATE TABLE [dbo].[LogFiles_Warehouse]
        (
        [id] [int] IDENTITY(1,1) NOT NULL,
        [timestamp] [datetime] NOT NULL,
        [clientNr] [int] NOT NULL,
        [server] [nvarchar](150) COLLATE Latin1_General_CI_AS NOT NULL,
        [storeNr] [int] NOT NULL,
        [account] [nvarchar](50) COLLATE Latin1_General_CI_AS NOT NULL,
        [software] [nvarchar](300) COLLATE Latin1_General_CI_AS NOT NULL,
        serverHash AS CAST(HASHBYTES('MD4', server) AS BINARY(16)),
        accountHash AS CAST(HASHBYTES('MD4', account) AS BINARY(16)),
        softwareHash AS CAST(HASHBYTES('MD4', software) AS BINARY(16))
        )

CREATE UNIQUE INDEX
        UX_LogFilesWarehouse_Server_Account_Software
ON      LogFiles_Warehouse (serverHash, accountHash, softwareHash)
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Using triggers + a smaller non-unique index for the most distinctive ields for helop alleviate the problem of table s.

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