Book Image

Developing Robust Date and Time Oriented Applications in Oracle Cloud

By : Michal Kvet
Book Image

Developing Robust Date and Time Oriented Applications in Oracle Cloud

By: Michal Kvet

Overview of this book

Proper date and time management is critical for the development and reliability of Oracle Databases and cloud environments, which are among the most rapidly expanding technologies today. This knowledge can be applied to cloud technology, on premises, application development, and integration to emphasize regional settings, UTC coordination, or different time zones. This practical book focuses on code snippets and discusses the existing functionalities and limitations, along with covering data migration to the cloud by emphasizing the importance of proper date and time management. This book helps you understand the historical background and evolution of ANSI standards. You’ll get to grips with data types, constructor principles, and existing functionalities, and focus on the limitations of regional parameters and time zones, which help in expanding business to other parts of the world. You’ll also explore SQL injection threats, temporal database architecture, using Flashback Technology to reconstruct valid database images from the past, time zone management, and UTC synchronization across regions. By the end of this book, you’ll be able to create and manage temporal systems, prevent SQL injection attacks, use existing functionalities and define your own robust solutions for date management, and apply time zone and region rules.
Table of Contents (26 chapters)
1
Part 1: Discovering Oracle Cloud
4
Part 2: Understanding the Roots of Date and Time
7
Part 3: Modeling, Storing, and Managing Date and Time
12
Part 4: Modeling Validity Intervals
17
Part 5: Building Robust and Secure Temporal Solutions
20
Part 6: Expanding a Business Worldwide Using Oracle Cloud

Transaction log structure and log types

Transaction logs describe the operations that are executed inside the transaction. Each log consists of the transaction position reference, the System Change Number (SCN), the individually performed operation, and the change vector. From this perspective, transaction logs can be divided into two groups – UNDO and REDO structures. An UNDO log stream stores the original data to allow the system to refuse transactions and revert individual operations to their original state. It is physically stored in the UNDO tablespace in the database. On the other hand, the REDO log stream is stored primarily in memory and then copied to the Online REDO log files, which are crucial to the Oracle database. This allows us to replay the approved transaction to get the state of the database just before the database instance or media failure. The Log Writer (LGWR) background process operates transaction log management.

Both streams are periodically overwritten...