Book Image

PHP Oracle Web Development: Data processing, Security, Caching, XML, Web Services, and Ajax

By : Yuli Vasiliev
Book Image

PHP Oracle Web Development: Data processing, Security, Caching, XML, Web Services, and Ajax

By: Yuli Vasiliev

Overview of this book

Oracle Database gets high marks for performance, reliability, and scalability. Building and deploying your PHP applications on Oracle Database enables you to combine the power and robustness of Oracle and the ease of use, short development time, and high performance of PHP. When used in a complementary way, PHP and Oracle allow you to build high-performance, scalable, and reliable data-driven Web applications with a minimum of effort.When building a PHP/Oracle application, you have two general options. The first is to use an Oracle database just to store data, performing all the operations on that data on the client side; the other is to use the database not only to store data, but also to process it, thus moving data processing to the data. While building the key business logic of a database-driven PHP application inside the database is always a good idea, you should bear in mind that not all of the databases available today allow you to do. The Oracle database, which offers record-breaking performance, scalability, and reliability, does. The partnership of Oracle and the open-source scripting language PHP is an excellent solution for building high-performance, scalable, and reliable data-driven web applications.This 100% practical book is crammed full of easy-to-follow examples. It provides all the tools a PHP/Oracle developer needs to take advantage of the winning combination. It addresses the needs of a wide spectrum of PHP/Oracle developers, placing the emphasis on the most up-to-date topics, such as new PHP and Oracle Database features, stored procedure programming, handling transactions, security, caching, web services, and Ajax.
Table of Contents (16 chapters)
PHP Oracle Web Development
Credits
About the Author
About the Reviewer
Preface

Transaction Isolation Considerations


When a transaction modifies a table row of a database, Oracle holds that row with a lock until the transaction is committed or rolled back. The purpose of doing this is to prevent two concurrent transactions from modifying the same row.

It is important to note here that locked rows can still be read by both the transaction that updates the rows and any other transaction. The difference between the two is that the transaction holding locks on the rows can see the changes immediately after the execution of the statement affecting the rows, whereas any other transaction cannot see those changes until the transaction that made them is committed.

While the locking mechanisms used in Oracle are discussed in detail in Oracle documentation (chapter Data Concurrency and Consistency in the Oracle Database Concepts manual), this section gives a brief overview of how transaction isolation works in PHP/Oracle applications.

What OCI8 Connection Function to Choose

I...