I work on sql severver 2019 I need to aks question
suppose i have table have 10 milions rows and i have cluster index on column StrtCountriesTiersID it as below
CREATE TABLE [dbo].[StrtCountriesTiers](
[StrtCountriesTiersID] [int] IDENTITY(1,1) NOT NULL,
[CountryId] [int] NULL,
[TierId] [int] NULL,
[ModifiedDate] [datetime] NULL,
[CreatedDate] [datetime] NOT NULL,
[Modifiedby] [int] NULL,
[CreatedBy] [int] NULL,
[CountryYear] [int] NULL,
CONSTRAINT [PK__StrtCountriesTiers__FEFAF27527F7A1C3] PRIMARY KEY CLUSTERED
(
[StrtCountriesTiersID] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF, IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS = ON, ALLOW_PAGE_LOCKS = ON) ON [PRIMARY]
) ON [PRIMARY]
GO
ALTER TABLE [dbo].[StrtCountriesTiers] ADD CONSTRAINT [DF__StrtCountriesTiers__ModifiedDate__215D38B9] DEFAULT (getdate()) FOR [ModifiedDate]
GO
ALTER TABLE [dbo].[StrtCountriesTiers] ADD CONSTRAINT [DF__StrtCountriesTiers__Creat__215D38B9] DEFAULT (getdate()) FOR [CreatedDate]
GO
so my question
Are creating noncluster index on column StrtCountriesTiersID after that
and include on nonclustered indexes will enhance performance
or that will make issue on performance and index seek