MSQL: A Multidatabase Language (original) (raw)

DATABASE CONNECTOR: A TOOL FOR MANIPULATION ON DIFFERENT DATABASES

A database is an organized list of facts and information that can easily be accessed, managed, and updated. Database management system is a software application that interacts with the user and the database itself to capture and analyze data. A general-purpose DBMS is designed to allow the definition, creation, querying, update, and administration of databases. There are many well-known DBMSs which include MySQL, MS Access Database, MS SQL Server, Oracle etc. A database is not generally portable across different DBMSs, but different DBMSs can interoperate by using standards such as SQL and ODBC or JDBC to allow a single application to work with more than one DBMS. This paper presents the salient features of developed DataBase Connector tool. The developed tool allows the user to perform DDL (Data Definition Language) and DML (Data Manipulation Language) command on different DBMSs including MS Access Database, SQL Server Database, SQL Express Database, XML Database and Oracle Server Database. The user has no need to have different software application to perform data definition and data manipulation operation on these different DBMSs.

Extending a multidatabase manipulation language to resolve schema and data conflicts

1995

The management of Multidatabase Systems (MDBS) is complicated by possible structural and semantic heterogeneity of the member database systems, and the requirements to preserve their local autonomy. Semantic heterogeneity is concerned with the di erences in the meaning and interpretation of similar data objects across the di erent systems. In loosely coupled database federations, static schema integration may be not feasible and heterogeneity con icts must be dealt with at the application level. Therefore, a multidatabase access language must be equipped accordingly with special features to resolve structural and semantic discrepancies.

SchemaSQL: An extension to SQL for multidatabase interoperability

ACM Transactions on Database Systems, 2001

We provide a principled extension of SQL, called SchemaSQL, that offers the capability of uniform manipulation of data and schema in relational multidatabase systems. We develop a precise syntax and semantics of SchemaSQL in a manner that extends traditional SQL syntax and semantics, and demonstrate the following. (1) SchemaSQL retains the flavor of SQL while supporting querying of both data

Multidatabase interoperability

1986

Many users now have an interest in simultaneoulsy accessing several databases. We present the main features of a prototype relational system designed specifically for this purpose.

SchemaSQL - A Language for Interoperability in Relational Multi-database Systems

We provide a principled extension of SQL, called SchemaSQL , that offers the capability of uni- form manipulation of data and meta-data in re- lational multi-database systems. We develop a precise syntax and semantics of SchemaSQL in a manner that extends traditional SQL syntax and semantics, and demonstrate the following. (1) SchemaSQL retains the flavour of SQL while sup- porting querying of both data and meta-data. (2) It can be used to represent data in a database in a structure substantially different from origi- nal database, in which data and meta-data may be interchanged. (3) It also permits the cre- ation of views whose schema is dynamically de- pendent on the contents of the input instance. (4) While aggregation in SQL is restricted to values occurring in one column at a time, SchemaSQL permits "horizontal" aggregation and even aggre- gation over more general "blocks" of informa- tion. (5) SchemaSQL provides a great facility for interoperability and dat...

Providing multidatabase access: an association approach

1993

One of the major tasks in the design of a multidatabase system (MDBS) is the de nition and maintenance of the global schema. Traditionally, this is accomplished by requiring the local databases participating in the MDBS to provide \export schemas" that are merged into a global schema. Resolution of schema and data incompatibilities, and mapping between local and global schemas are, in general, very di cult tasks that must be performed at the multidatabase level. We believe that a solution to this formidable problem may lie in the shifting of responsibility for these tasks to the local level. We propose a model in which the MDBS administrator de nes the global schema as a view that is to be maintained by e a c h of the participating databases. The MDBS layer supports submission and processing of (global) queries expressed over a union of such views. Each participating database must provide a view of its database that conforms to the global speci cation and must promise to respond to queries formulated over this view. We discuss the architecture of such systems and the problems involved in the processing of global queries.

An intermediate database language and its rule-based transformation to different database languages

Data & Knowledge Engineering, 1987

A user or a comptuter system which extracts information from heterogeneous DBMS faces the hard problem of dealing with different target database languages for each DBMS. We propose a solution for this problem based on an intermediate database language and its rule-based transformation to target languages. This solution is implemented in the database access module of the Intelligent Database Assistant, developed at GTE Laboratories. We describe the intermediate database language GTE DELPHI, which combines the power of relational algebra with practically important database operations, including output to a file, grouping, aggregate computations, and nested queries. We show how to convert GTE DELPHI to different relational and 4th generation database languages by a rule-based transformation system and indicate how a conversion program can be generated from examples. Translation from a high-level user language (such as English) to GTE DELPHI is simplified by using a universal relation version of GTE DELPHI as an intermediate step.

A data preparation framework based on a multidatabase language

Proceedings 2001 International Database Engineering and Applications Symposium, 2001

Integration and analysis of data from different sources have to deal with several problems resulting from potential heterogeneities. The activities addressing these problems are called data preparation and are supported by various available tools. However, these tools process mostly in a batch-like manner not supporting the iterative and explorative nature of the integration and analysis process. In this work we present a framework for important data preparation tasks based on a multidatabase language. This language offers features for solving common integration and cleaning problems as part of query processing. Combining data preparation mechanisms and multidatabase query facilities permits applying and evaluating different integration and cleaning strategies without explicit loading and materialization of data. The paper introduces the language concepts and discusses their application for individual tasks of data preparation.

A classification of multi-database languages

Parallel and Distributed Information …, 1994

This paper defines a formal classification of multidatabase languages into five levels of database integration with increasing degree of global control and decreasing degree of local autonomy. First, the fundamental interoperability mechanisms are identified for each of these levels. Their consequences on local autonomy as well as implementation draw-backs are discussed. Second, various multi-database languages are classified into these categories. In addition to our own language COOL ~, other proposals are analyzed, including SQL *Net, Multibase, Superviews, VODAK, Pegasus, and O*SQL. 195 0-8186-6400-2/94 $4.00