Slowly Changing Dimensions Are Not Always as Easy as 1, 2, 3

To kick off our first column of the year, we're going to take on a challenging subject that all designers face: how to deal with changing dimensions. Unlike most OLTP systems, a major objective of a data warehouse is to track history. So, accounting for change is one of the analyst's most important responsibilities. A sales force region reassignment is a good example of a business change that may require you to alter the dimensional data warehouse. We'll discuss how to apply the right technique to account for the change historically. Hang on to your hats — this is not an easy topic.

Installing and Configuring SQL Server Reporting Services

In this chapter, we discuss various installation setups you can use to install and configure Reporting Services. For the most part, this process is managed by the Setup.exe installation wizard, so expect to be prompted for a number of configuration options that determine how, where, and whether each segment of the Reporting Services package will be installed. We know that there are a variety of ways to install Reporting Services, so we've tried not only to address the common case, but also provide hints and techniques to be used for some of the more sophisticated installation scenarios. To make this process as painless as possible, we've broken this chapter down into several sections:

MDX Essentials: The CROSSJOIN() Function: Breaking Bottlenecks

In this article, we will return to a function we introduced in an earlier article, CROSSJOIN(), whose mission it is to combine two sets of dimension members into one. We will discuss how CROSSJOIN() works in general, and then discuss how its performance can become an issue in medium to large-sized data sets. We will then undertake a multiple-step practice example intended to assist us in gaining an understanding of the issues, before exposing approaches to minimizing the performance overhead that we can encounter in using CROSSJOIN() to reach our reporting and analysis needs.

The HAVING and GROUP BY SQL clauses

This month's topic is one that often baffles inexperienced SQL coders. We will look at the GROUP BY clause, and then the difference between conditions placed in the WHERE clause, and the HAVING clause. I have used MySQL to test all of the examples, but most of them should work without any problems on other DBMS' too.

Secure options for remote SQL Server administration

In this two-part series, Serdar Yegulalp explains how to remotely administer SQL Server without compromising network security. In part one below, he describes two methods for providing secure administrative access to remote employees. In part two, he'll examine practical problems you may encounter when remotely administering SQL Server and how to work around them.

Surrounding the ETL Requirements

November 13, 2004 / Issue TOC

Surrounding the ETL Requirements

Before designing an ETL system, you must first understand all of your business needs.

By Ralph Kimball , Margy Ross

Ideally, the design of your extract, transform, and load (ETL) system begins with one of the toughest challenges: surrounding the requirements. By this we mean gathering in one place all the known requirements, realities, and constraints affecting the ETL system. The list of requirements is pretty overwhelming, but it's essential to lay them on the table before launching a data warehouse project.

The requirements are mostly things you must live with and adapt your system to. Within the framework of your requirements, you'll have many places where you can make your own decisions, exercise your judgment, and leverage your creativity, but the requirements are just what they're named. They are required.

Using Parent Package Variables in Package Configurations

Package configurations are now the prescribed way of being able to set values within your package from an outside source. One of the options for the source is Parent Package Variable. The name is perhaps a little misleading so this article is meant to guide you through this slight confusion and into using them. It also helps to explain a key concept in SQL Server Integration Services

usp_import_from_mysql

Imports data from MySQL Server; works best with mysql driver 3.51.06! You'll have to create a dsn and then a linked server to that dsn. The script checks if the table exists in the mysql catalog (defined in the dsn properties). Too bad it needs administrative privileges to run (dbcc statement) - my advice: don't […]

SQL Server 2000 Reporting Services Activation Process

SQL Server 2000 Reporting Services uses cryptography to protect account data. Learn how SQL Server 2000 Reporting Services generates and stores the keys required to encrypt data.

Using a Subquery in a T-SQL Statement

Sometimes the criteria for determining which set of records will be affected by a SELECT, UPDATE, DELETE and/or INSERT statement cannot be obtained by hard coding the selection criteria. Occasionally there is a need to use the results of a SELECT statement to help determine which records are returned or are affected by a T-SQL statement. When a SELECT statement is used inside another statement, the inside SELECT statement is known as a subquery. Subqueries can help to dynamically control the records affected by an UPDATE, DELETE or INSERT statement, as well as to help determine the records that will be returned by a SELECT statement. This article will show different examples of how to use a subquery to help clarify the records affected or selected by a T-SQL statement.