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The designers of RMAN aimed at integration with Oracle database servers, [citation needed] providing block-level corruption detection during backup and restore processes. [ citation needed ] RMAN optimizes performance and space-consumption during backup with file multiplexing and backup-set compression; it integrates with Oracle Secure Backup ...
In database management systems, block contention (or data contention) refers to multiple processes or instances competing for access to the same index or data block at the same time. In general this can be caused by very frequent index or table scans, or frequent updates.
Data cleansing or data cleaning is the process of identifying and correcting (or removing) corrupt, inaccurate, or irrelevant records from a dataset, table, or database. It involves detecting incomplete, incorrect, or inaccurate parts of the data and then replacing, modifying, or deleting the affected data. [ 1 ]
There are two types of data corruption associated with computer systems: undetected and detected. Undetected data corruption, also known as silent data corruption, results in the most dangerous errors as there is no indication that the data is incorrect. Detected data corruption may be permanent with the loss of data, or may be temporary when ...
For example, if a user UPDATEs a salary-value in a table containing employee-related data, the DBMS generates a redo record containing change-vectors that describe changes to the data segment block for the table. And if the user then COMMITs the update, Oracle generates another redo record and assigns the change a "system change number" (SCN).
Isolation is typically enforced at the database level. However, various client-side systems can also be used. It can be controlled in application frameworks or runtime containers such as J2EE Entity Beans [2] On older systems, it may be implemented systemically (by the application developers), for example through the use of temporary tables.
Data corruption and/or loss caused by the entry of invalid data or commands, mistakes in database or system administration processes, sabotage/criminal damage etc. Ross J. Anderson has often said that by their nature large databases will never be free of abuse by breaches of security; if a large system is designed for ease of access it becomes ...
In computing (specifically data transmission and data storage), a block, [1] sometimes called a physical record, is a sequence of bytes or bits, usually containing some whole number of records, having a maximum length; a block size. [2] Data thus structured are said to be blocked. The process of putting data into blocks is called blocking ...