Patent ID: 7162472
Filing Date: 2007-01-09
Classification: G06F,Y10S

Abstract:
1. A method for notifying a client of a change to data stored at a database, the method comprising: receiving a subscription from the client, the subscription selecting a first subset of data from within a set of data; generating a subscription plan for filtering the first subset from within the set of data; receiving a query to be executed at the database, the query changing a second subset of data within the set of data; generating a query plan for executing the query, the query plan for filtering the second subset from within the set of data; matching the subscription to the query based on the set of data; supplementing the query plan with the subscription plan; prior to executing the supplemented query plan, evaluating the supplemented query plan whereby the subscription filters the first subset of data from within the second subset of data to form a third subset of data; determining based on the third set of data whether or not to generate a notification of the change to the third subset of data such that the notification is generated when the third subset of data is non-empty, and the notification is not generated when the third set of data is empty; and after evaluating the supplemented query plan, executing the query by changing the second subset of data.