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

摘要

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.

主权项

1. A method for providing data services to an application, comprising:
receiving, by a data access system, application data modifications that modify instances of the application, the application data modifications being expressed according to an application schema; extracting the application data modifications from a client cache that are to be persisted to a relational database, wherein the client cache is a cache operatively coupled to a server associated with the relational database; generating a mapping view that maps a relationship between the application and the relational database, a mapping of the mapping view being specified using a declarative language and being compiled into bidirectional views; and utilizing incremental view maintenance to materialize object instances that have changed in accordance with the mapping to translate the application data modifications into relational database modifications expressed according to a database schema for updating the relational database, utilizing incremental view maintenance comprising:
applying at least one view maintenance rule that specifies a view operator, and given the application data modifications, produces the relational database modifications;identifying a minimum set of affected store tables in the database based on a set of changed materialized object instances;identifying a minimum set of changes to a given store table based on a set of changed materialized entity instances based at least in part on an entity data model;generating a dependency graph based on the set of changed materialized entity instances, wherein a node of the dependency graph represents an operation on a table of the relational database of a set of operations, and an edge in the dependency graph indicates that there is a dependency between two nodes connected by the edge, a dependency indicating that a first operation on the table relies on a result of having already performed a second operation;ordering the set of operations based on the dependency graph; andsubmitting the set of operations to the relational database based on the order.