Microsoft Technology Licensing, LLC

Google Inc.

Microsoft Corporation

Sergey Melnik

Philip Alan Bernstein

Atul Adya

Yevgeniy Kogan

Rajesh Rao

Colin Joseph Meek

Zlatko Michailov

Alan P Nash

Per-Ake Larson

Eric Hugh Veach

Ramachandran Venkatesh

Narayanan Shivakumar

Jose A Blakeley

David John Nettleton

Jason Todd Hunter

Laramie Leavitt

Theodore Vassilakis

Matthew B Tolton

James Felger Terwilliger

Todd J Green

Peter Mork

Andrey Gubarev

Alexander Thomson

Dale Woodford

Nathan Bales

Geoffrey M Romer

Methods, systems, and apparatus, including computer programs encoded on computer storage media, for restarting a query using a token. One of the methods includes receiving, by a computer from a requesting device, a query; determining, using a data storage system, a current result responsive to the query; generating, using the current result, a restart token that represents operations performed to determine a plurality of results responsive to the query including the current result responsive to the query and that can be used to determine a new result responsive to the query that was not included in the plurality of results responsive to the query; and providing, to the requesting device, a message that includes a) first data for the restart token that represents operations performed to determine the plurality of results responsive to the query and b) second data for the current result responsive to the query.

Query restartability

Application data is synchronized with a database where changes to object data maintained by an application is expressed according to an application schema. Changes to the object data are identified as corresponding to an entity schema. Changes to views of database tables are applied by translation rules to the set of changed entities. The database tables conforming to a database schema are thereafter updated.

View maintenance rules for an update pipeline of an object-relational mapping (ORM) platform

A database update pipeline may be incorporated into a data access architecture for providing data services to applications, thereby bridging the gap between application data and data as persisted in databases. The update pipeline has the ability to translate changes made to object instances into data store change constructs, and carry those changes over to a data store. Such a pipeline can also advantageously perform the reverse operation, allowing applications to query using the database update pipeline, and receive materialized object instances.

A multiversioned position-space indexing system is disclosed. The system includes data structures for maintaining a multiversioned position space including a multi-versioned filter merge list which represents many versions of a changing position space in a very compact form and a position shift map which describes how to translate stored positions in many different log-structured merge tree layers into logical positions at a particular timestamp. Each log-structured merge tree layer can be divided into two sublayers: a final sublayer and a correction sublayer. The final sublayer contains index entries added after the layer's start timestamp and remain live as of the layer's final timestamp as well as deletion makers for index entries that were inserted before the layer's start timestamp, but deleted before the layer's final timestamp. The correction layer contains index entries that were both created and deleted between the start and end timestamps of the layer.

System for indexing collections of structured objects that provides strong multiversioning semantics

Described is programmatic access to persistent XML and relational data from applications based upon explicit mappings between object classes, XML schema types, and relations. The mappings are used in data access, that is, they drive query and update processing. A query may be processed into a query for accessing the XML data and another query for second type for accessing the relational data. Mappings support strongly-typed classes and loosely-typed classes, and may be conditional upon other data, may decouple query and update translation performed at runtime from schema translation used at compile time, and/or may be compiled into transformations that produce objects from XML data and transformations that produce XML data from objects. Mappings may be generated automatically or provided by the developer.

Mapping and query translation between XML, objects, and relations

A data access architecture is provided that includes a mapping architecture for mapping data as may be used by an application to data as persisted in a database. The mapping architecture makes use of two types of mapping views&#x2014;a query view that helps in translating queries and an update view that helps in translating updates. Incremental view maintenance can be used to translate data between the application and database.

Mapping architecture with incremental view maintenance

A data access architecture may includes a mapping architecture for mapping data as may be used by an application to data as persisted in a database. Such a mapping architecture uses two types of 'mapping views'&#x2014;one for translating queries and the other for translating updates. A mechanism is provided that automatically generates query and update views from high-level mapping specifications. A validation may be performed to ensure that a mapping specification, when used in conjunction with a mapping architecture, allows data to 'roundtrip' from the application to the database, without loss of data.

Generation of query and update views for object relational mapping

Systems and methodologies that facilitate evolving a data model via a combination of an explicit logical model definition, logical model changes, functional units, an explicit/implicit physical model and physical model changes, to derive a data model transformation are presented. Such an arrangement can provide for a rich set of transformations, which can be automatically applied to a data model instantiation. The subject invention facilitates leveraging a common set of code in data model instantiation evolution, by defining the set of transformations across an arbitrary data model.

Data model and schema evolution

A system that facilitates composition of schema mappings. A general algorithm is provided for composing a broad class of mappings, where one or both mappings are not functions, such as constraints between two schemas and the inverse of functions. A composition component performs composition on schema mappings of disparate data sources, which schema mappings can be expressed by at least one of full, embedded, and second-order dependencies, wherein the second-order dependencies need not be in source-to-target form. The algorithm for composition further includes a procedure that tests whether the composition algorithm will terminate.

System and method for composition of mappings given by dependencies

A general-purpose reusable algebraic-based composition algorithm for composing mappings between data schemas. The algorithm handles more expressive mappings, makes a best-effort to eliminate symbols when a perfect answer cannot be obtained, includes new heuristics, and is extensible. A relational algebraic language is provided wherein each mapping is expressed as a set of constraints, and each constraint is either a containment or equality of two or more relational algebraic expressions. The composition mechanism exploits monotonicity properties of algebraic operators in operator arguments, handles NULLs and bag semantics, operates to allow composition to produce a partial result when a complete result is not possible, facilitates symbols elimination one symbol at a time using left composition, for example, as a way of isolating the symbols, supports making a best-effort to eliminate as many symbols as possible from an intermediate schema, and handles unknown or partially known operators via delayed handling.

Mapping composition using algebraic operators

A system and method facilitating data access operations is provided. The system can facilitate an executable, instance-level interaction between a source model (e.g., schema) expressed in a first metamodel (e.g., object-oriented metamodel) and a target model expressed in a second metamodel (e.g., SQL metamodel). The system can produce instance mappings to round-trip the data between the source schema and the generated target schema. Further, an abstraction component can be employed to translate the data access operations on the object model into SQL queries and updates.

Growing community of inventors

Kirkland, WA, United States of America

Sergey Melnik