Data change tracking and event notification

摘要

The described implementations relate to updating views in a database system. One implementation can identify an active view that retrieves records from a database and determine one or more physical tables in the database that are referenced by the active view. The implementation can track one or more columns in the physical tables that are used by the active view and identify a change to the physical tables in a transaction log of the database. If the change does not affect the one or more columns, the change can be treated as an ignorable change for the active view.

主权项

1. A method comprising:
identifying a first active view that retrieves records from a database; determining one or more physical tables in the database that are referenced by the first active view; tracking one or more first columns in the one or more physical tables that are used by the first active view; identifying a change to the one or more physical tables in a transaction log of the database; in a first instance when the change does not affect the one or more tracked first columns, treating the change as an ignorable change for the first active view; in the first instance, identifying a second active view that returns an individual second column that is affected by the change or that is conditioned on the individual second column that is affected by the change; and in the first instance, recomputing the second active view so that the second active view reflects the change, wherein the transaction log is separate from the one or more physical tables and includes both:
data that was included in the one or more physical tables of the database before the change was made to the one or more physical tables, andother data that was included in the one or physical tables of the database after the change was made to the one or more physical tables.