Martin Cairns, Senior BI Consultant (blog | twitter). Martin is a consultant with Purple Frog Systems a Business Intelligence & Data Warehousing Consultancy. He provides expertise for some of the UK's most prestigious clients including ASOS, AOL and Tesco. Martin has been working with SQL Server since 1998 and currently is specialising on data warehousing projects incorporating SQL Server and Analysis Services. With extensive experience designing and optimising multi-terabyte data warehouses, he particularly enjoys troubleshooting problems that occur at high scale, having successfully delivered a variety of BI projects across sectors including Banking, Insurance, Media and Retail. Passionate about the SQL community Martin can often be found sharing knowledge on the forums, on Twitter and is a regular face at community events.