Databases Archives

Power Query Formula Language in Power BI Desktop

The Power Query Formula Language (PQFL) is a functional language that drives the Power BI transformations, and allows you to...

21 September 2015 19 min read

David Njoku

Introduction to Analytic Functions (Part 2)

In the first part of this series I introduced you to the analytic functions family, outlined its close relationship to...

17 September 2015 7 min read

Uwe Ricken

How Forwarded Records are Read and Processed in a SQL Server Heap

Before you deliberately use a heap in SQL Server rather than a table, it is worth understanding why a heap...

09 September 2015 16 min read

Gail Shaw

How to Confuse the SQL Server Query Optimizer

Gail Shaw examines three common forms of generic SQL that can and will confuse the SQL Server Optimizer to the...

09 September 2015 35 min read

David Njoku

Introduction to Analytic Functions (Part 1)

Analytic functions have been part of Oracle for a very long time now – ever since 8i back in 1999....

07 September 2015 10 min read

Dwain Camps

SQL Conditional JOIN: Why It’s Slow & What to Use Instead

Learn why conditional JOINs using CASE in the ON clause cause poor SQL Server performance. Compare alternatives: LEFT OUTER JOIN...

07 September 2015 14 min read

Kathi Kellenberger

T-SQL Window Functions Speed Phreakery

Before SQL Server had SQL window functions, SQL Server developers had to use all manner of tricks and algorithms to...

27 August 2015 12 min read

Robert Sheldon

Working with SQL Server data in Power BI Desktop

What's the best way of providing self-service business intelligence (BI) to data that is held in on-premise SQL Server? Not,...

24 August 2015 24 min read

Tony Davis

Basic SQL Server Performance Troubleshooting For Developers

The speed of a slow SQL Query can almost always be improved. In SQL Server, the query optimizer determines the...

14 August 2015 39 min read

Anju Garg

TSPITR Using ACFS Snapshots

Starting with Oracle Grid Infrastructure 12c (12.1), Oracle Cloud File system (ASM Cluster File System in cluster environment) supports database...

10 August 2015 16 min read

Robert Sheldon

The Evolution of SQL Server BI

It is sometimes hard to keep up with Microsoft's direction in Business Intelligence. Over the years, we've been presented with...

27 July 2015 14 min read

Anju Garg

Integrating ACFS Snapshots With RMAN

In my last article, I demonstrated that starting with Oracle Grid Infrastructure 12c (12.1), Oracle Cloud File system (ASM Cluster...

14 July 2015 10 min read

Jonathan Lewis

Basics of the Cost Based Optimizer – Part 4

In the first three installments of this series I outlined the mechanisms used by Oracle to analyze a very simple...

09 July 2015 14 min read

Satishbabu Gunukula

Why Virtual Private Catalog?

Recovery Manager (RMAN) is the preferred tool to backup and recover the Oracle Database. You can use recovery catalog or...

08 July 2015 8 min read

David Njoku

Anatomy Of A SELECT Statement – Part 3: Recursive Subquery Factoring

We need a baritone voiceover man. You know how those huge TV shows – 24, Prison Break, Jane the Virgin...

07 July 2015 7 min read

Ravi Kumar

Upgrading A Database Using Recovery Manager (RMAN) Duplicate Command In Oracle 12c

Introduction For versions of Oracle 11g R2, Oracle Recovery Manager (RMAN) replicates a database to a different Oracle home and...

03 July 2015 12 min read

Anju Garg

12c: Database Backups Using ACFS Snapshots

Starting with Oracle Grid Infrastructure 12c (12.1), Oracle Cloud File system (ASM Cluster File System in cluster environment ) supports...

29 June 2015 11 min read

Jonathan Lewis

Basics of the Cost Based Optimizer – Part 3

In the second installment of this series we looked at individual access paths for the tables in a simple join...

25 June 2015 14 min read

Robert Sheldon

How to Get NULLs Horribly Wrong in SQL Server

NULLs in SQL are a mixed blessing. The Three-Valued Logic of SQL has its uses but can cause difficulties to...

25 June 2015 36 min read

Jonathan Lewis

Basics of the Cost Based Optimizer – Part 2

In the first installment of this series I gave an informal description of how the optimizer would consider the possibilities...

17 June 2015 15 min read