Search results
Results from the WOW.Com Content Network
[1] [2] Data redundancy can also be used as a measure against silent data corruption; for example, file systems such as Btrfs and ZFS use data and metadata checksumming in combination with copies of stored data to detect silent data corruption and repair its effects.
Oracle provides both graphical user interface (GUI) and command-line (CLI) tools for managing Data Guard configurations. Data Guard supports both physical standby and logical standby sites. Oracle Corporation makes Data Guard available only as a bundled feature included within its "Enterprise Edition" of the Oracle RDBMS. [1]
An example of a data-integrity mechanism is the parent-and-child relationship of related records. If a parent record owns one or more related child records all of the referential integrity processes are handled by the database itself, which automatically ensures the accuracy and integrity of the data so that no child record can exist without a parent (also called being orphaned) and that no ...
Data corruption can occur at any level in a system, from the host to the storage medium. Modern systems attempt to detect corruption at many layers and then recover or correct the corruption; this is almost always successful but very rarely the information arriving in the systems memory is corrupted and can cause unpredictable results.
Physical data model options. [1] A physical data model (or database design) is a representation of a data design as implemented, or intended to be implemented, in a database management system. In the lifecycle of a project it typically derives from a logical data model, though it may be reverse-engineered from a given database implementation.
A logical journal stores only changes to file metadata in the journal, and trades fault tolerance for substantially better write performance. [9] A file system with a logical journal still recovers quickly after a crash, but may allow unjournaled file data and journaled metadata to fall out of sync with each other, causing data corruption.
1 logical to 1 physical chunk dup 1 logical chunk to 2 physical chunks on 1 block device raid0 N logical chunks to N≥2 physical chunks across N≥2 block devices raid1 1 logical chunk to 2 physical chunks across 2 out of N≥2 block devices, [92] in contrast to conventional RAID 1 which has N physical chunks raid1c3 1 logical chunk to 3 ...
System developers can set up CDC mechanisms in a number of ways and in any one or a combination of system layers from application logic down to physical storage. In a simplified CDC context, one computer system has data believed to have changed from a previous point in time, and a second computer system needs to take action based on that ...