Design overview of inter-session warnings in IBM DB2 Universal Database

The following article mainly introduces the design overview of implementing inter-session warnings in the IBM DB2 general database. In some cases, do you want to migrate your database from the Oracle database to IBM?®DB2®Universal Database™? Do you think a special feature of Oracle may be lost?

DB2 UDB is such a flexible database that can meet many of your needs. In this article, I will introduce how to implement a function called warning. Warning is used to allow communication between multiple sessions.

Warning Overview

Warnings are designed to deliver messages between sessions. The warning identifier, session identifier, and message are stored in the table alerts. dbms_alert_info ). A message is sent by one session and then read by another session. This process is controlled by a flag set in the specified table. When designing parameters such as column length, host variable length, and polling interval, you need to know the migration from Oracle to DB2. You can increase the warning name and message length as needed.

Design overview of inter-session warnings in IBM DB2 Universal Database

The following objects are required to implement warning functions similar to Oracle. All objects are included in the download section of this article:

Table storing warning information: alerts. dbms_alert_info

Register the warning stored procedure: alerts. register

Stored Procedures for deleting Warnings: alerts. remove and alerts. delete

Stored Procedure for sending warning messages: alerts. signal

Stored Procedure for receiving warning messages: alerts. waitone and alerts. waitany

Implement the delayed UDF: alerts. delay

UDF that implements session identity: alerts. session_id

You can change my design to meet your special requirements. All objects use a common mode, that is, warning. Design stored procedures so that you can extend them to capture SQLCODE, SQLSTATE, and ERROR_MESSAGE. A large number of exception handling is implemented in all the stored procedures listed above, but it is not used here. You can cancel the annotation of the exception handling section in the sample code before using this section.

They can also return the corresponding return code to implement the required operations in the main language. The cursor can be implemented in all stored procedures, but in some cases you may want to change to fullselect. All warning objects are granted Public execute permission. You should use the DBADM or SYSADM permission to create all these objects. The above content is an introduction to the design overview of implementing inter-session warnings in the IBM DB2 general database.

The above content is an overview of the design of implementing inter-session warnings in the IBM DB2 general database. I hope it will help you in this regard.