Abstract:
One embodiment of the present invention provides a system that automatically sends a notification about a database event. The system operates by receiving a number of items, including a registration of a specified event-type, a subscription of a protocol for the notification, a format for the notification, and a list of recipients for the notification. The system then configures the database to send the notification about the specified event-type to the specified list of recipients in the specified format via the specified protocol. Adding this notification capability at the database-level enhances the functionality and interoperability of many applications as well as providing more robust and timely information to the appropriate audiences.

Description:
BACKGROUND  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to computers and databases. More specifically, the present invention relates to a method and apparatus for automatically sending a notification about a database event in a specified format via a specified protocol to a specified list of recipients.  
           [0003]    2. Related Art  
           [0004]    The advent of e-commerce has led to the rapid development of web servers and database platforms. The number of new dynamic web applications continues to grow exponentially, and as a result, the underlying web servers and databases become increasingly complex with more and more functionality.  
           [0005]    Currently, users of these databases write their applications to interact with the data stored in the database, but usually must rely on all transactions taking place within their application. The problem exists, however, that if the data is edited directly in the database, and thereby circumvents the application, some critical change might be missed by an interested party that the application was designed to notify. Note that this problem becomes increasingly more complex as multiple applications are written to interact with one common database. In addition, users and applications want to be notified of more and more database events as they happen.  
           [0006]    Currently, the only methods of accomplishing this are through proprietary formats specified by the database provider, if they even exist at all. For instance, a technician might want to receive an email and a notification on his or her pager when the database server halts, or a manager might want a notification when the number of sales of a certain item surpasses the one-thousand mark.  
           [0007]    What is needed in this situation is a method and an apparatus that generates and sends a notification to a list of clients in a specified presentation format via a specified protocol.  
         SUMMARY  
         [0008]    One embodiment of the present invention provides a system that automatically sends a notification about a database event. The system operates by receiving a number of items, including a registration of a specified event-type, a subscription of a protocol for the notification, a format for the notification, and a list of recipients for the notification. The system then configures the database to send the notification about the specified event-type to the specified list of recipients in the specified format via the specified protocol. Adding this notification capability at the database-level enhances the functionality and interoperability of many applications as well as providing more robust and timely information to the appropriate audiences.  
           [0009]    In one embodiment of the present invention, the system determines if the database event is of the specified event-type, and then sends the notification about the specified event-type to the specified list of recipients in the specified format via the specified protocol.  
           [0010]    In one embodiment of the present invention, the system receives the event at a queue.  
           [0011]    In one embodiment of the present invention, the system receives the event at a queue that is persistent.  
           [0012]    In one embodiment of the present invention, the system receives the event at a queue that consists of records stored in a database table.  
           [0013]    In one embodiment of the present invention, an event monitor determines if the event is of the specified event-type.  
           [0014]    In one embodiment of the present invention, the notification is sent to multiple parties.  
           [0015]    In one embodiment of the present invention, the event-types include: a client shutting down, a database shutting down, a stack overflowing, a trigger firing, a database record operation being performed, and a database error occurring.  
           [0016]    In one embodiment of the present invention, the available protocols include Oracle Call Interface (OCI), Programming Language/SQL (PL/SQL), Simple Mail Transfer Protocol (SMTP), Hyper Text Transfer Protocol (HTTP), Wireless Application Protocol (WAP), and Simple Network Management Protocol (SNMP).  
           [0017]    In one embodiment of the present invention, the available formats include Extensible Markup Language (XML), Hyper Text Markup Language (HTML), Wireless Markup Language (WML), Structured Query Language (SQL), and raw data.  
           [0018]    In one embodiment of the present invention, the notification includes a command sent to a database to perform an action and a command sent to a computer to perform a task. 
       
    
    
     BRIEF DESCRIPTION OF THE FIGURES  
       [0019]    [0019]FIG. 1 illustrates a computer system containing a database with the mechanism for the automatic notification of events in accordance with an embodiment of the present invention.  
         [0020]    [0020]FIG. 2 illustrates a queue within the mechanism for automatic notification in accordance with an embodiment of the present invention.  
         [0021]    [0021]FIG. 3 illustrates a rule within the queue in accordance with an embodiment of the present invention.  
         [0022]    [0022]FIG. 4 is a flowchart illustrating the process of creating a registration of a specific event-type and a subscription for the notification of the event-type in accordance with an embodiment of the present invention.  
         [0023]    [0023]FIG. 5 is a flowchart illustrating the process by which the database receives an event-type, determines if there are any subscriptions for the specified event-type, and if so, sends a notification about the specified event-type in accordance with an embodiment of the present invention.  
         [0024]    [0024]FIG. 6 is a flowchart showing the use of the mechanism for automatic notification of events in a workflow application in accordance with an embodiment of the present invention.  
     
    
     DETAILED DESCRIPTION  
       [0025]    The following description is presented to enable any person skilled in the art to make and use the invention, and is provided in the context of a particular application and its requirements. Various modifications to the disclosed embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the present invention. Thus, the present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein.  
         [0026]    The data structures and code described in this detailed description are typically stored on a computer readable storage medium, which may be any device or medium that can store code and/or data for use by a computer system. This includes, but is not limited to, magnetic and optical storage devices such as disk drives, magnetic tape, CDs (compact discs) and DVDs (digital versatile discs or digital video discs), and computer instruction signals embodied in a transmission medium (with or without a carrier wave upon which the signals are modulated). For example, the transmission medium may include a communications network, such as the Internet.  
         [0027]    Computer System  
         [0028]    [0028]FIG. 1 illustrates a computer system  100  containing a database  102  with a mechanism for the automatic notification of events in accordance with an embodiment of the present invention. The computer system  100  illustrated in FIG. 1 includes a database  102 , which contains a database instance  104 , a shadow process  106 , and advanced queues  108 . Note that advances queues contains a s-specific queue  122 .  
         [0029]    During system operation, shadow process  106  enqueues an event, which the event monitor process  110  then receives through shared memory communication  112 . Event monitor process  110  then notifies a client process  116  on a client computer system  114  via a specified protocol and format that the event took place.  
         [0030]    Computer system  100  and client computer system  114  can generally include any type of computer system, including, but not limited to, a computer system based on a microprocessor, a mainframe computer, a digital signal processor, a portable computing device, a personal organizer, a device controller, and a computational engine within an appliance. Note that client computer system  114  can alternatively be part of computer system  100 .  
         [0031]    Database  102  can include any type of system for storing data in nonvolatile storage. This includes, but is not limited to, systems based upon magnetic, optical, and magneto-optical storage devices, as well as storage devices based on flash memory and/or battery-backed up memory.  
         [0032]    Client computer system  114  communicates with computer system  100  through a network  120 . Network  120  can generally include any type of wire or wireless communication channel capable of coupling together computing nodes. This includes, but is not limited to, a local area network, a wide area network, or a combination of networks. In one embodiment of the present invention, network  120  includes the Internet.  
         [0033]    Event Queue  
         [0034]    [0034]FIG. 2 illustrates the structure of queue  122  within the mechanism for automatic notification in accordance with an embodiment of the present invention. Among other items, queue  122  contains subscription table  202 . Within subscription table  202 , there are a number of rules  204 - 208 , which contain information specifying rules for performing notifications. Note that subscription table  202  may or may not be a table within database  102 .  
         [0035]    Subscription Rule  
         [0036]    [0036]FIG. 3 illustrates a rule  204  within queue  122  in accordance with an embodiment of the present invention. Rule  204  contains an event-type  300  upon which to trigger a notification, a recipient list  302  to whom the notification is to be sent, and a notification format  304 . Note that recipient list  302  may include, but is not limited to, pagers, email addresses, fax machines, event logs, and even other queues.  
         [0037]    Process of Registering for a Notification  
         [0038]    [0038]FIG. 4 is a flowchart illustrating the process of creating a registration of a specific event-type as well as a subscription for the notification of the event-type in accordance with an embodiment of the present invention. The system starts by determining the type of event to trigger a notification, and then registering that event-type (step  400 ). Next, the system adds the subscription rules for the notification (step  402 ). Note that these subscription rules can specify where the notification is to be delivered. Then, the system registers the protocol by which the notification will be delivered (step  404 ). Finally, the system registers the presentation format for the notification (step  406 ).  
         [0039]    Process of Sending a Notification  
         [0040]    [0040]FIG. 5 is a flowchart illustrating the process by which the database receives an event-type, determines if there are any subscriptions for the specified event-type, and if so, sends a notification about the specified event-type in accordance with an embodiment of the present invention. When an event takes place (step  500 ), shadow process  106  checks to see if there are any subscriptions for the specified event-type (step  502 ). If there are no subscriptions, the process is finished for the specified event. If subscriptions do exist, shadow process  106  publishes the specified event information to the event monitor via shared memory communication  112  (step  504 ). Next, shadow process  106  checks to see if event monitor  110  process is running (step  506 ), and starts event monitor process  110  if it is not (step  508 ).  
         [0041]    Event monitor  110  then reads the subscription from the shared memory (step  510 ) and looks up and prepares the list of clients to receive the notification (step  512 ). Event monitor  110  then looks up the protocol and format of the notification (step  514 ) and performs the notification (step  516 ).  
         [0042]    Workflow Example  
         [0043]    [0043]FIG. 6 is a flowchart showing the use of the mechanism for automatic notification of events in a workflow application in accordance with an embodiment of the present invention. In this embodiment, the mechanism for automatic notification of events is a key piece of a hiring workflow system.  
         [0044]    In this workflow application, a hiring manager first posts job requirements internally (step  600 ). Human resources representatives then receive notification from the database that a hiring request has been posted to the database (step  602 ). Next, an interview process takes place (step  604 ), and an appropriate candidate is chosen (step  606 ). The hiring manger then posts a message with the candidate&#39;s information, their comments, and the interviewer&#39;s comments (step  608 ).  
         [0045]    Next, the hiring manager&#39;s supervisor and the appropriate approvers receive notification from the database that their action is required (step  610 ). Finally, the approvers approve or reject the hiring request (step  612 ) and the hiring manger receives notification from the database that his or her request has been approved or rejected (step  614 ).  
         [0046]    The foregoing descriptions of embodiments of the present invention have been presented for purposes of illustration and description only. They are not intended to be exhaustive or to limit the present invention to the forms disclosed. Accordingly, many modifications and variations will be apparent to practitioners skilled in the art. Additionally, the above disclosure is not intended to limit the present invention. The scope of the present invention is defined by the appended claims.