Data consistency refers to the state in which data in an information system or database is maintained in accordance with defined rules and standards. It means that the stored data is free from contradictions and adheres to the expected requirements and integrity rules. Data consistency is a critical aspect of data management and plays a vital role in ensuring the reliability and quality of data within a system.
There are various aspects of data consistency, including:
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Logical consistency: This pertains to adhering to established data rules and structures. Data should be stored in accordance with defined business rules and data models.
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Temporal consistency: Data should be consistent at different points in time, meaning that when you access data, it should be in line with other data in the system at a specific time.
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Transactional consistency: In a multi-user system, data consistency rules should be maintained during data changes and transactions. Transactions should either be fully executed or not at all to avoid inconsistencies.
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Physical consistency: This relates to data integrity at the physical storage level to prevent data corruption and loss.
Maintaining data consistency is crucial to ensure that data is reliable and accurate, which, in turn, supports the quality of business decisions and processes in organizations. Database management systems (DBMS) provide mechanisms to support data consistency, including transaction controls, integrity constraints, and data backup techniques.