\chapter{Background}\label{ch:background}

In this chapter, we describe the problems in efficiently answering
Y and Z queries, and discuss why these queries are so important
for web portals.
We also consider the task of determining how effective an indexing
scheme is, with respect to various data distributions.
Finally, we survey previous attempts at providing indexing schemes
that lead to efficient execution of Y and Z queries.

\section{Y and Z queries}

Blah blah blah Y and Z blah blah blah.

\section{Evaluating indexing effectiveness}

Blah blah blah indexing effectiveness blah blah blah.

\section{Previous work}

Blah blah blah previous work blah blah blah.
Which presumably contains references~\cite{dapd2004} as well.
Blah blah blah previous work blah blah blah.
