What is primary key How can we design a good primary key?

What is primary key How can we design a good primary key?

What Makes a Good Primary Key?

1. The primary key should consist of one column whenever possible.
2. The name should mean the same 5 years from now as it does today.
3. The data value should be non-null and remain constant over time.
4. The data type should be either an integer or a short, fixed-width character.

Why you should never use GUIDs as part of Clustered Index?

The problem with clustered indexes in a GUID field are that the GUIDs are random, so when a new record is inserted, a significant portion of the data on disk has to be moved to insert the records into the middle of the table.

When to use GUID for identity / primary key?

A clustered index on identity column the table was causing latch contention, due to which I had to move clustered index to a candidate key. So, if the table is for OLTP purpose, I would suggest creating primary with non-clustered index & use GUID column for a clustered index.

Can a GUID be used as a clustering key?

GUIDs may seem to be a natural choice for your primary key – and if you really must, you could probably argue to use it for the PRIMARY KEY of the table. What I’d strongly recommend not to do is use the GUID column as the clustering key, which SQL Server does by default, unless you specifically tell it not to.

How to create a GUID in SQL Server?

) ALTER TABLE dbo.MyTable ADD CONSTRAINT PK_MyTable PRIMARY KEY NONCLUSTERED (PKGUID) CREATE UNIQUE CLUSTERED INDEX CIX_MyTable ON dbo.MyTable (MyINT)

Can a GUID column be an identity column?

Yes, from the perspective that you can have the identity column be a unique clustered index to take advantage of inserts being append-only to the table, and you can have a nonclustered primary key on your GUID column for both security and uniqueness when locating records. Any other settings I should place on the table?