Reprinted from: http://blog.csdn.net/leshami/article/details/5731158One, rollback (ROLLBACK) and undo (undo)Rollback and roll forward are important means of ensuring that the data in an Oracle database is in a consistent state. --Before the 9i
Oracle transaction row-Level Lock storage point rollback commit. Note that A and B are not two ORACLE accounts, but two connection sessions. The above is just
Oracle transaction row-Level Lock storage point rollback commit. Note that A and B are not
triggers cannot invoke or indirectly invoke a DCL statement such as Commit,rollbackDDL statements and Commit,rollback statements cannot be run in triggersDDL statements: DDL statement terms define and manage objects in the database, such as
Undo tablespace and rollback segments
The Undo/rollback tablespace is the tablespace used to store rollback segments. The rollback segment is the data space of the image before Oracle saves the modified data. Each rollback segment contains some
Before looking at this article, make sure that you understand the concept of Oracle transactions and locks as it is, but do not understand, refer to the consistency and atomicity of database transactions and Oracle TM and TX Locks1. Commit a
All along, it is assumed that connection if Setautocommit (false) is set, the manual transaction commit must be initiated manually or rollback. There was a problem today and the results were very surprising.The results were tested as follows (note
Start transaction,COMMIT, AndROLLBACKSyntax
From: http://dev.mysql.com/doc/refman/5.0/en/commit.html
Of course, the article noted from MySQL, but MySQL, SQL Server, Oracle start tracmsaction, commit, and rollback syntax are no problem in DML.
I hope
(1). insufficient space for rollback segments
ORA-01562-failed to extend rollback segment number string
The reason for insufficient rollback segment space is generally as follows:
A. The remaining free space in the tablespace where the rollback
Here I will only briefly introduce these two commands, but they are used in the process of use. So I will mention them here. If you are interested in this, you can search for more introductions. Please share them ~~
A Database Transaction starts
1. Concepts
Transaction uses the extent in the rollback segment in a round-robin manner. When the current extent is full, it is moved to the next extent. Multiple transactions may write data to the same extent at the same time, but only one
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