12 November 2009
12 November 2009

Managing Transaction Logs in SQL Server

The Transaction Log provides the means by which either the complete set of tasks of a database transaction are performed or none of them are. It ensures that , via rollback, only valid data is written out to the database, and it allows transactions to be played back to recreate the system state right before a failure. Robert Sheldon explains the various basic tasks involved in managing the transaction log.… Read more
03 August 2009
03 August 2009

Introduction to Change Data Capture (CDC) in SQL Server 2008

Change Data Capture records INSERTs, UPDATEs, and DELETEs applied to SQL Server tables, and makes a record available of what changed, where, and when, in simple relational 'change tables' rather than in an esoteric chopped salad of XML. These change tables contain columns that reflect the column structure of the source table you have chosen to track, along with the metadata needed to understand the changes that have been made. Pinal Dave explains all, with plenty of examples in a simple introduction.… Read more
03 August 2009
03 August 2009

An Introduction to SQL Server FileStream

Filestream allows us to store and manage unstructured datain SQL Server more easily. Initially, the accounts of FILESTREAM assumed prodigious powers of concentration and cognition, and we mortals all recoiled numbly. However, it became clear that we were missing out on some extraordinarily useful functionality, so we asked Jacob Sebastian to come up with a simple and clear-cut account of the FILESTREAM feature in SQL Server 2008. You'll agree he has managed the feat superbly.… Read more
07 May 2009
07 May 2009

SQL and the Snare of Three-Valued Logic

The whole subject of the Three-Valued (also known as ternary, trivalent or 3VL) Logic of SQL tends to trip people up. This is hardly surprising in view of the fact that it involves an esoteric Polish mathematician and because it behaves differently in the DDL (Data Declaration Language) and the DML (Data Manipulation Language). In response to requests, Joe Celko comes to the rescue and makes it all seem simple.… Read more
07 May 2009
07 May 2009

Facts and Fallacies about First Normal Form

When discussing the normalisation process, it is always the First Normal Form that causes the most grief and confusion. Anith Sen takes up the challenge to explain, in simple terms, exactly what the First Normal Form really is, and why it is so important for Database Design. Along the way, he dispels some of the myths that have grown up around 1NF.… Read more
29 December 2008
29 December 2008

SQL Server 2008: Performance Data Collector

With Performance Data Collector in SQL Server 2008, you can now store performance data from a number of SQL Servers in one central location. This data is collected by a collection set on each server and stored in a shareable management data warehouse (MDW). Reports can be generated from this data using the built-in reports or generating your own with reporting Services. Brad McGehee explains more. … Read more
25 November 2008
25 November 2008

SQL Server Index Basics

Given the fundamental importance of indexes in databases, it always comes as a surprise how often the proper design of indexes is neglected. It often turns out that the programmer understands detail, but not the broad picture of what indexes do. Bob Sheldon comes to the rescue with a simple guide that serves either to remind or educate us all!… Read more
20 June 2008
20 June 2008

How to Track Down Deadlocks Using SQL Server 2005 Profiler

It is irritating, sometimes alarming, for the user to be confronted by the 'deadlock message' when a deadlock happens. It can be a tiresome business to prevent them from occurring in applications. Fortunately, the profiler can be used to help DBAs identify how deadlocking problems happen, and indicate the best way of minimising the likelihood of their reappearance.… Read more
01 April 2008
01 April 2008

The Concept of Cardinal Reciprocity- A Primer

Too many authors in the field of relational theory have neglected the concept of Cardinal Reciprocity. This can cause a number of subtle problems with database design in terms of its derivability, redundancy, and consistency. . Increasingly, this little-understood aspect of relational theory, that emphasises the cardinality of the attributes of tuples in a relation and the reciprocity with isomorphic foreign key restraints, is becoming a hot forum topic.… Read more