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COMPUTER SOFTWARE APPLICATION - CITS




           6  Hash Functions: Use cryptographic hash functions to create checksums or hashes of data. Comparing these
              hashes can reveal any unauthorized changes to the data.
           7  Data  Verification:  Periodically  verify  the  accuracy  and  consistency  of  data  through  reconciliation  and
              verification processes.
           8  Data Governance: Establish data governance policies and procedures to enforce data integrity standards
              across the organization.
           Types of data integrity

           There are mainly four types of Data Integrity:
           1  Domain Integrity
           2  Entity Integrity
           3  Referential Integrity
           4  User-Defined Integrity

           Domain Integrity
           Domain, in this context, pertains to the acceptable values within a specified range. It denotes the scope of values
           that can be utilized and stored in a specific database column. The available data types primarily include integers,
           text, and dates, among others. It’s important that any input entered into a column falls within the permissible range
           of the associated data type.

           Example-To store employee salaries in the ‘employee_table,’ it’s possible to implement constraints that permit only
           integer values. Any input that deviates from this requirement, like text or character-based data, would be declined,
           and the Database Management System (DBMS) would generate error messages to indicate the violation of the
           defined constraint. This helps ensure that only valid integer values are accepted for salary entries in the database,
           maintaining data consistency and accuracy.






















           Entity Integrity

           Every row representing an entity in a database table must have a distinct means of identification.
           This is typically achieved using primary keys, which serve as unique identifiers for each record.
           It’s essential to enforce the entity constraint, which specifies that the primary key value must not be NULL.
           This requirement ensures that every record in the database has a specific and non-null primary key value.
           When the primary key value is not NULL, it becomes possible to distinguish records from one another, even if all
           other field values are identical. In essence, primary keys enable the unequivocal identification of each individual
           record in the database.

           Example: In a customer database with a ‘customer_table’ containing attributes like age and name, it’s crucial to
           ensure that each customer can be uniquely identified. Sometimes, there might be two customers with identical
           names and ages, leading to confusion when retrieving data. To address this challenge, primary keys are assigned



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                              CITS : IT&ITES - Computer software application - Lesson 18 - 36
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