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Title On efficiently implementing SchemaSQL on a SQL database system
 
Names LAKSHMANAN, LVS
SADRI, F
SUBRAMANIAN, SN
Date Issued 1999 (iso8601)
Abstract SchemaSQL is a recently proposed extension to SQL for enabling multi-database interoperability. Several recently identified applications for SchemaSQL, however, mainly rely on its ability to treat data and schema labels in a uniform manner, and call for an efficient implementation of it on a single RDBMS. We first develop a logical algebra for SchemaSQL by combining classical relational algebra with four restructuring operators - unfold, fold, split, and unite - originally introduced in the context of the tabular data model by Gyssens et al. [GLS96], and suitably adapted to fit the needs of SchemaSQL. We give an algorithm for translating SchemaSQL queries/views involving restructuring, into the logical algebra above. We also provide physical algebraic operators which are useful for query optimization. Using the various operators as a vehicle, we give several alternate implementation strategies for SchemaSQL queries/views. All the proposed strategies can be implemented non-intrusively on top of existing relational DBMS, in that they do not require any additions to the existing set of plan operators. We conducted a series of performance experiments based on TPC-D benchmark data, using the IBM DB2 DBMS running on Windows/NT. In addition to showing the relative tradeoffs between Various alternate strategies, our experiments show the feasibility of implementing SchemaSQL on top of traditional RDBMS in a non-intrusive manner. Further more, they also suggest new plan operators which might profitably be added to the existing set available to relational query optimizers, to further boost their performance.
Genre Proceedings Paper
Topic Logic
Identifier PROCEEDINGS OF THE TWENTY-FIFTH INTERNATIONAL CONFERENCE ON VERY LARGE DATA BASES,471-482