Books for you

There is only one way to deal successfully with the issues raised by concurrent data
access. The database that provides the access must implement strategies to transparently
overcome the potential problems posed by concurrent access. Fortunately,
Oracle has excellent methods for handling concurrent access.
This chapter describes the basics of concurrent data access and gives you an overview
of the way that Oracle handles the issues raised by concurrent access. If you??™ve
worked with large database systems in the past and are familiar with concurrent user
access, you might want to skip the first section of this chapter.
Basics of Concurrent Access
Before you can understand the problems posed by multiuser concurrent access to
data, you need to understand the basic concepts that are used to identify and
describe those potential concurrency issues.
Transactions
The transaction is the bedrock of data integrity in multiuser databases and the foundation
of all concurrency schemes. A transaction is defined as a single indivisible piece
of work that affects some data.


Pages:
394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418