Query rewriting for semistructured data

Yannis Papakonstantinou, Vasilis Vassalos
1999 SIGMOD record  
We address the problem of query rewriting for TSL, a language for querying semistructured data. We develop and present an algorithm that, given a semistructured query q and a set of semistructured views V, nds rewriting queries, i.e., queries that access the views and produce the same result as q. Our algorithm is based on appropriately generalizing containment mappings, the chase, and uni cation techniques that were developed for structured, relational data. We also develop an algorithm for
more » ... ivalence checking of TSL queries. We show that the algorithm is sound and complete for TSL, i.e., it always nds every TSL rewriting query of q, and we discuss its complexity. W e extend the rewriting algorithm to use available structural constraints such as DTDs to nd more opportunities for query rewriting. We currently incorporate the algorithm in the TSIMMIS system.
doi:10.1145/304181.304222 fatcat:gfvtf3nbgjcyvdhcaotkjv4qpi