33 results about "Relational algebra" patented technology

A system disclosed includes a temporal data warehouse and a platform independent temporal data warehouse load application operable to run on the system. The load application uses timestamp data from incoming data in conjunction with a relational algebra of set operators to identify and sequence net changes between the incoming data and data previously stored within the data warehouse. The load application loads the identified and sequenced net changes into the data warehouse with relatively little intrusion into normal operation of the data warehouse. Optimizations, including but not limited to, distinct partitioning of the workload into parallel streams are selectable via metadata.

A computer system provides the ability to construct and edit a Data Definition File (DDF) containing hierarchically related elements of data, some of which are dynamic in that they must execute in order to produce or retrieve data. A client computer system having knowledge of a DDF appropriate for its uses sends a request to a server, which contains or can retrieve the DDF requested by the client. The request contains parameters used by the server to customize the resulting keyed data file for the client's purposes. Upon receipt of the request, the server copies the DDF into a coupled memory, performs requested parameter substitutions, and executes dynamic elements to produce resulting data elements. The process is repeated recursively for all elements of the hierarchical structure, until no dynamic elements remain, then the resulting keyed data file is returned to the client for its uses. Data elements may be derived from a plurality of sources, and these sources may be combined and manipulated using a plurality of data operations, including relational algebra or structured query language, enabling joins and merges between multiple sources and formats. An Authoring System is provided which assists in the construction and validation of DDFs.

A structured natural language query and knowledge system is provided to allow a user who lacks programming skills to enter a database query or a rule in the form of a structured natural language sentence. The scope of the sentence is preferably defined by an improved object relational query language, an object relational algebra, or both. Command and conditions that appear in natural language form are defined with corresponding formal query texts. A user is prompted to compose a structured natural language sentence using the defined commands and conditions. The user-selected command and its arguments appear as the verb phrase of a structured natural language sentence. The user-selected conditions and their parameters appear as the adjective phrases of the sentence. The sentence is parsed and changed into a translated formal query text for formal database query and rule processing.

An extensible markup language (XML) expression included in a query is parsed to yield an abstract syntax tree. The abstract syntax tree is then transformed into a unified tree including XML algebra operations. The unified tree is then converted into a relational tree including enhanced relational algebra operations. The relational tree is then forwarded to a query processor for optimization and execution of the query at the query processor.

The present invention provides a database capable of integrated query processing and a data processing method thereof. The database capable of integrated query processing includes: a storage unit configured to store data including relational data, and graph data; a converter configured to convert a query language for a property graph data model for processing the graph data into a relational algebra that is a statement in an intermediate stage; and a controller configured to control the converter so as to convert the query language for the property graph data model in an input integrated query into a syntactic statement structure, and convert the query language for the property graph data model included in the query into the relational algebra, when the integrated query, in which the query language for the property graph data model and the relational query language are mixed, is input.

Techniques for constructing a software application are provided. A data model of the application is represented as a relational model. Control logic of the application is defined as a mapping from a current state of the application data model and one or more application inputs to a new state of the application data model and one or more application outputs, described by relational algebra components.

The invention relates to an XML database query method based on the relational algebra range operation, the method is that: converting the expression of XPath query path to an integral query range, utilizing an effective storage of B-tree index and index XML; converting an easy XPath query path to a range query directly. The invention has the advantages of utilizing an integer range query to realize the XPath query for XML because relational engine is based on the B-tree index, adopting a comparative query searching data corresponding to the primary key, while the integer comparative operation is the fastest in computer, avoiding the overhead of character string matching operation for such realization, and having high efficiency.

A method and system provide an algebraic database management system (ADBMS) that maintains ADBMS type system. The type system includes an ADBMS type database (ATD) and provides a collection of rules that assign a type to constructs. The ATD is a catalog with each record holding typing information. An interpreter dynamically processes, at execution time, a query (that is syntactically modeled on relational algebra). The interpreter: determines inputs of the query; searches the ATD for a data type of each of the inputs, determines compatibility between each of data types of the inputs based on an operator of the query, determines a resultant of the query and a data type of the resultant (based on the operator of the query), and saves the resultant of the query by adding a new record in the catalog.

The embodiment of the invention provides a query execution method and device, electronic equipment and a computer readable medium, and relates to the field of databases. The method comprises the following steps: converting a sub-query in a received SQL request to obtain a relational algebraic expression corresponding to the sub-query; determining a part, which can be pushed downwards to be executed by child nodes in a distributed database, in the relational algebra expression; and converting a part, which can be pushed down to be executed by a child node in a distributed database, in the relational algebraic expression to obtain an SQL instruction used for indicating the child node to execute related operations of the child query. According to the embodiment of the invention, the sub-queries are pushed downwards to the sub-nodes in the distributed database to be executed, and the sub-nodes of the distributed database are effectively combined to execute the sub-queries, so that the overall computing power of the distributed database can be completely utilized, and the computing pressure of an execution server in a distributed database system is effectively relieved.

A method and apparatus for constructing a software application with a plurality of screens. Operations performed in the method include representing a data model of the computer application as a relational model, providing a first screen of the computer application representing a current state of the data model, using relational algebra to define control logic of the computer application as a mapping from the current state of the data model and zero or more current application inputs to a new state of the data model and zero or more application outputs, using relational algebra to specify the selection of a second screen as a function of the current state of the data model and zero or more current application inputs, and generating computer executable code displaying the first screen and the second screen on a display.

The invention discloses a distributed query optimization method of an equivalent expansion method based on relational algebra, and the method comprises the steps: sending a request, converting a language, constructing a query tree, optimizing fragments, decomposing the query tree, judging whether connection operation exists or not, calculating benefits and judging whether traversal is completed ornot. The method is scientific and reasonable in structure and safe and convenient to use. According to the method, the traditional SQl language is converted into the relational algebra expression byutilizing the consistency of the SQL language and the relational algebra, so that the efficiency of distributed query is indirectly improved, and the query tree is decomposed in the process of constructing the query tree, so the characteristic of data discrete distribution of a distributed system is better met, the data coupling between queries is reduced, the communication overhead is correspondingly reduced, the connection process is optimized through the MapReduce method, the communication overhead between stations in the connection process is greatly reduced, and the communication time iscorrespondingly shortened, so the query efficiency is improved.

A database implemented by storing information encoded in DNA molecules provides high information density but the information is more difficult to access than in conventional electronic storage media.A relational database is a way of organizing information by using multiple related tables. Relational algebra operations are performed on relational databases to locate and manipulate information. This disclosure provides techniques for implementing relational algebra operations on a relational database that uses DNA molecules to store information. The techniques of this disclosure relate to the structure of DNA molecules used to store the information and to correlations between relational algebra operations and manipulations of DNA molecules.

In the linear location referencing system (LRS) domain, one of the key challenges is joining LRS segments from different datasets by their common spatial (spatiotemporal) existence. The invented LRS join algorithm is based on relational algebra that provides high performance along with algorithmic clarity. It addresses what the prior art has failed to address or address performantly.

The invented algorithm first generates a cell mesh for each route, which is then used to decompose the segments participating in the join operations. The resulting segments are determined based on the cell population configuration. Finally, the results are coalesced to keep LRS datasets compact and normalized.

The invention provides a query method and a query system based on a general query language, and belongs to the technical field of query engines. The method comprises: converting query content into a relational algebra expression, and obtaining query features of the relational algebra expression by analyzing the relational algebra expression; matching the query engine features with the query features, calculating the cost required by each query engine for meeting the query features, and selecting the query engine with the minimum cost; performing query optimization on the relational algebraic expression by using a query optimization rule bound with a query engine, and performing related query feature rewriting at the same time; calling a specific query engine adaptation service for the rewritten query features, converting the query features into a query language of a target engine, and submitting the target query language to the query engine for query to obtain a query result; and writing the query result into an external storage module, notifying a user that the query is finished, and acquiring the query result by the user through access connection.