Pathfinder

You have reached the site of the relational XQuery compiler Pathfinder. At the core of this research project lies our desire to answer the question

"How far can we push relational database technology to construct an efficient and scalable XQuery implementation?"

If you are interested in a copy of Pathfinders SQL code generator and/or MonetDB/XQuery please have a look at the Download page. If you are interested in the ideas and the technology behind Pathfinder please have a look at the Technology and the Publications pages. If you just want to get a first overview please read on.

Pathfinder

Pathfinder is a re-targetable query compiler that turns XQuery expressions into relational algebra queries. Based on the algebraic representation a large series of optimizations transforms the query into an efficient evaluation plan before producing either SQL or MonetDB specific execution code.

MonetDB/XQuery: Pathfinder and MonetDB

MonetDB/XQuery integrates the Pathfinder compiler into the MonetDB product and furthermore extends it with runtime extensions for offline and online shredding, serialization (with multiple serialization modes), efficient path step algorithms such as Staircase Join, and support for updates.

MonetDB/XQuery inherits the scalability of its database back-end: you may feed XML documents beyond 1GB size into the system and still expect reasonable, interactive query response times (for example, with the XMark benchmark).

SQL Code Generator Pathfinder and DB2

In our next release we will ship Pathfinder with a SQL code generator that turns XQuery expression into SQL queries. We have tested the generated SQL code mainly on DB2 v9. B-tree indexes faithfully speed up the range predicates that implement XPaths location step semantics.