Oracle Block scn/commit scn/cleanout scn description 1. description: The cache header part of the Block records a block scn, which is the timestamp of the last change of the current Block. To be exact, this update does not refer to the latest update
Transaction and two phase commit, three-phase commit protocol (finite state automata)
• Acid for 1 transactionsA transaction is the fundamental to ensure that a database is permanently changed from one consistent state to another, where acid is the
[Oracle]-[impact of COMMIT on indexes]-from trace, we can see the impact of COMMIT on indexes. Recently, due to work requirements, there is a task involving data migration, therefore, I have been paying attention to the time-consuming issue of
To avoid implicit commit or rollback, make sure that only one or more DML operations are submitted or rolled back. This prevents subsequent DCL or DDL operations from automatically submitting the previous D
To avoid implicit commit or rollback, make
Definition of implicit commit
It is also known as automatic submission, that is, the process of executing the commit statement is not displayed, and the operations in the session are automatically submitted to the database.
Implicit submission
1.
Distributed transactions are transactions that occur between multiple databases. Oracle uses the dblink Method for transaction processing. distributed transactions are much more complex than standalone transactions. Most customs
Distributed
The Oracle COMMIT statement is expected to help you understand it. The following describes how to process the Oracle COMMIT statement.
Oracle COMMIT statement processing sequenceWhen a transaction is committed, Oracle assigns a unique sequence
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
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
Compare the impact of a single COMMIT and multiple COMMIT on the waste of log space while changing the data volume.
The LGWR process writes online logs in sequence and does not skip in the middle, and the LGWR process does not write twice in the
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