Type inference for queries on semistructured data

Tova Milo, Dan Suciu
1999 Proceedings of the eighteenth ACM SIGMOD-SIGACT-SIGART symposium on Principles of database systems - PODS '99  
We study the problem of type checking and type inference for queries over semistructured data. Introducing a novel traces technique, we show that the problem is difficult in general (NP-complete), but can be solved in PTIME for many practical cases, including, in particular, queries over XML data. Besides being interesting by itself, we show that type inference and the related traces technique have several important applications, facilitating query formulation, optimization, and verification.
more » ... finition 2.1 Let G be a data graph and S be a schema. We say that G conforms to S if there exists a mapping I-from the nodes in G to types in S s.t.:
doi:10.1145/303976.303998 dblp:conf/pods/MiloS99 fatcat:x323vhzoyrg4lb6jg4oamupcxu