Solved

10777 - Dimension table indexes

Posted on 2014-07-18
1
424 Views
Last Modified: 2014-07-22
Hi experts,

i am reading about
Dimension table indexes:
Create a nonclustered primary key index
Create a clustered business key index

but i do not understand
Create a nonclustered primary key index
why nonclustered?

this is the script
CREATE TABLE DimProduct
(ProductKey int identity NOT NULL PRIMARY KEY NONCLUSTERED,
 ProductAltKey nvarchar(10) NOT NULL,
 ProductName nvarchar(50) NULL,
 ProductDescription nvarchar(100) NULL,
 ProductCategoryName nvarchar(50))
GO

 CREATE TABLE DimGeography
 (GeographyKey int identity NOT NULL PRIMARY KEY NONCLUSTERED,
  PostalCode nvarchar(15) NULL,
  City nvarchar(50) NULL,
  Region nvarchar(50) NULL,
  Country nvarchar(50) NULL)
GO

 CREATE TABLE DimCustomer
(CustomerKey int identity NOT NULL PRIMARY KEY NONCLUSTERED,
 CustomerAltKey nvarchar(10) NOT NULL,
 CustomerName nvarchar(50) NULL,
 CustomerEmail nvarchar(50) NULL,
 CustomerGeographyKey int NULL REFERENCES DimGeography(GeographyKey))
GO


 CREATE TABLE DimSalesperson
(SalespersonKey int identity NOT NULL PRIMARY KEY NONCLUSTERED,
 SalesPersonAltKey nvarchar(10) NOT NULL,
 SalespersonName nvarchar(50) NULL,
 StoreName nvarchar(50) NULL,
 StoreGeographyKey int NULL REFERENCES DimGeography(GeographyKey))

 CREATE TABLE DimDate
 (DateKey int NOT NULL PRIMARY KEY NONCLUSTERED,
  DateAltKey datetime NOT NULL,
  CalendarYear int NOT NULL,
  CalendarQuarter int NOT NULL,
  MonthOfYear int NOT NULL,
  [MonthName] nvarchar(15) NOT NULL,
  [DayOfMonth] int NOT NULL,
  [DayOfWeek] int NOT NULL,
  [DayName] nvarchar(15) NOT NULL,
  FiscalYear int NOT NULL,
  FiscalQuarter int NOT NULL)
GO
  -- CREATE A FACT TABLE
  CREATE TABLE FactSalesOrders
  (ProductKey int NOT NULL REFERENCES DimProduct(ProductKey),
   CustomerKey int NOT NULL REFERENCES DimCustomer(CustomerKey),
   SalespersonKey int NOT NULL REFERENCES DimSalesperson(SalespersonKey),
   OrderDateKey int NOT NULL REFERENCES DimDate(DateKey),
   OrderNo int NOT NULL,
   ItemNo int NOT NULL,
   Quantity int NOT NULL,
   SalesAmount money NOT NULL,
   Cost money NOT NULL
    CONSTRAINT [PK_ FactSalesOrder] PRIMARY KEY NONCLUSTERED
 (
      [ProductKey],[CustomerKey],[SalesPersonKey],[OrderDateKey],[OrderNo],[ItemNo]
 )
 )
GO
0
Comment
Question by:enrique_aeo
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
1 Comment
 
LVL 15

Accepted Solution

by:
Vikas Garg earned 250 total points
ID: 40204318
Hi,

Type of indexing in dimension Tables

1) Apply clustered index on surrogate key & non-clustered index on natural key of the dimension which will help key lookup in the ETL process.

1st option is best if you use Analysis Services & MOLAP cube

2) Apply clustered index on the natural key and non-clustered index on the surrogate key.

2nd option is better to avoid lock escalation

Hope this would clear your doubts ....
0

Featured Post

VIDEO: THE CONCERTO CLOUD FOR HEALTHCARE

Modern healthcare requires a modern cloud. View this brief video to understand how the Concerto Cloud for Healthcare can help your organization.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

In the first part of this tutorial we will cover the prerequisites for installing SQL Server vNext on Linux.
In part one, we reviewed the prerequisites required for installing SQL Server vNext. In this part we will explore how to install Microsoft's SQL Server on Ubuntu 16.04.
This video shows, step by step, how to configure Oracle Heterogeneous Services via the Generic Gateway Agent in order to make a connection from an Oracle session and access a remote SQL Server database table.
Via a live example, show how to setup several different housekeeping processes for a SQL Server.

631 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question