Abstract: A fast and efficient system and method for retrieving data from a database system by a process external to the database system is provided, in which the database system accepts and processes data requests in a second query language in response to data queries issued in a first query language by the external process. The system comprises an interface module operatively coupled to the external process and the database system. Upon receiving a data query in the first query language from the external process, the interface module generates an equivalent data request in the second query language and sends the data request to the database system for processing and data retrieval. The interface module then transfers the retrieved data from the database system to the module and returns the 4data to the external process. The interface module operates as a plurality of independent co-operating processes handling at least in part concurrently various steps of the data query processing.

Abstract: The present invention introduces a mechanism to partition the processing work required on data from a variety of proprietary OLAP data sources in such a way that as much as possible of the processing can be carried out by the OLAP data source, thereby improving the efficiency of the delegated portion of the operations, and making more effective use of the overall processing power of the computing facilities. By decomposing the required high level expressions into sub-expressions to be applied to data elements some part of the expressions can be evaluated by the OLAP data source. The results of these sub-expressions are combined by the OLAP data engine to produce the same result as the original full expression. ‘Rows’ and ‘columns’ of the original cross-tabulation formed from the data are classified as either simple—meaning the expression can be processed at the OLAP data source or complex—meaning such expressions cannot be computed at the OLAP data source.

Abstract: A metadata model defines model objects to represent one or more data sources. The metadata model comprises a data access layer, a business layer and a package layer. The data access layer contains data access model objects. The data access model objects include a data access model object that describes how to retrieve data from the data sources. The business layer contains business model objects. The business model objects include a business model object that describes a business view of data in the data sources. The package layer contains package model objects which reference subsets of business model objects.

Abstract: Metadata exchanging for importing metadata from one or more external sources of metadata into a metadata model is described. A metadata extracted from an external source is in a source format specific to the external source. The metadata model uses a model format. The metadata exchange translates the metadata in the source format into one or more model objects in the model format, and then import the model objects into the metadata model.

Abstract: A query engine formulates a data source query to obtain data from one or more data sources. The query engine uses a metadata model containing model objects that represent the data sources. The metadata model has a data access layer, business layer and package layer. The model objects of the business layer are constructed based on the model objects contained in the data access layer. The query engine interacts to the metadata model at the business layer, and formulates a data source query based on a query specification provided by a client application. Thus, the query engine allows use of different type of client applications to obtain reports from one or more data sources.