This article is part of the [[Advanced User's Guide]] and introduces the available index structures, which are utilized by the query optimizer to rewrite expressions and speed up query evaluation.
Nearly all examples in this article are based on the [http://files.basex.org/xml/factbook.xml factbook.xml] document. To see how a query is rewritten, please turn on the [[GUI#Visualizations|Info View]] in the GUI or use the [[Startup_OptionsCommand-Line Options#BaseX_Standalone|-V flag]] on command line.
=Structural Indexes=