哪种方法更适合这种情况?

我们有下表:

CREATE TABLE [dbo].[CampaignCustomer](
    [ID] [int] IDENTITY(1,1) NOT NULL,
    [CampaignID] [int] NOT NULL,
    [CustomerID] [int] NULL,
    [CouponCode] [nvarchar](20) NOT NULL,
    [CreatedDate] [datetime] NOT NULL,
    [ModifiedDate] [datetime] NULL,
    [Active] [bit] NOT NULL,
 CONSTRAINT [PK_CampaignCustomer] PRIMARY KEY CLUSTERED 
(
    [ID] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON) ON [PRIMARY]
) ON [PRIMARY]

CREATE UNIQUE NONCLUSTERED INDEX [IX_CampaignCustomer_CouponCode] ON [dbo].[CampaignCustomer] 
(
    [CouponCode] ASC
)WITH (PAD_INDEX  = OFF, STATISTICS_NORECOMPUTE  = OFF, SORT_IN_TEMPDB = OFF, IGNORE_DUP_KEY = OFF, DROP_EXISTING = OFF, ONLINE = OFF, ALLOW_ROW_LOCKS  = ON, ALLOW_PAGE_LOCKS  = ON, FILLFACTOR = 20) ON [PRIMARY]
GO

我们使用CouponCode和其他外键执行非常稳定的查询(为了简单起见,上面没有显示)。CampaignCustomer表有近400万条记录,而且还在不断增长。我们也做活动,不需要优惠券代码,因此我们不插入这些记录。现在,我们还需要开始跟踪这些活动,还有另一个目的。所以我们有两个选择:

2. 为此特定目的创建一个单独的表以跟踪所有活动。