DataGuides: Enabling Query Formulation and Optimization in Semistructured Databases

摘要: In semistructured databases there is no schema fixed in advance. To provide the benefits of a such environments, we introduce DataGuides: concise and accurate structural summaries databases. DataGuides serve as dynamic schemas, generated from database; they are useful for browsing database structure, formulating queries, storing information statistics sample values, enabling query optimization. This paper presents theoretical foundations along with an algorithm their creation overview incremental maintenance. We performance results based on our implementation Lore DBMS data. also describe use Lore, both user interface to enable structure formulation, means guiding processor optimizing execution.