Looking for some advice regarding a table / index design decision I've got to make on some tables that I've got to port into SQL server from an existing 4GL based database.
I've got a product history table that is inserted into frequently (never updated) and the table has this kind of structure
- ProductNo String(20)
- CreatedDateTime DateTime
- Description String(100)
At the moment the primary key is made up of a combination of ProductNo and CreatedDateTime in an attempt to define a unique index key. We can have many records per productno.
I'll be creating some 1 to 1 related tables and don't want to carry both the productno and the createddatetime fields into the related tables to act as foriegn keys. I also think this combination is a little fragile in order to guarantee uniqueness.
So, I'm planning to add a new field to the table 'ProductHistoryPK' as an incrementing Int or SequentialGuid to act as the primary key and a foreign key to related tables.
In terms of indexes I'm thinking of creating
- Non-clustered primary key on the new ProductHistoryPK field.
- Clustered Index on the ProductNo field as this is field that is often searched on.
Any thoughts or pointers regarding this?
ProductNois searched on often doesn't really qualify it as the clustering key, in my opinion. See my answer for what you should consider when picking your clustering key - a
varchar(20)column isn't really well suited....