Ralph Hughes in his book Agile Data Warehousing for the Enterprise writes:
"Even with all the previous tactics, the team will still need to write many queries that cannot employ bridging or point-in-time tables. These queries will involve a good number of outer joins and correlated subqueries and thus be difficult to write and maintain. Fortunately, EDW developers do not have to resign themselves to manually writing such complex joins every time they need a new query. They can either acquire a query writer from the hyper normalization community or build one of their own...EDW leaders opting for hyper normalization should include some time for tuning query writers into their project plans."
Can any elaborate on the query writers mentioned and the type of tuning needed?