If the Quick Cart database were not normalized, several potential data anomalies could arise. Here are some of the most common types of anomalies that may occur:
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Insertion Anomalies:
- Data Dependency Issues: A new product might need to be inserted into the database, but if the product information is stored with customer information in a single table, you won't be able to add the new product without also creating a new customer entry.
- Missing Data: In an unnormalized database, you may not be able to add a new category without also having to input irrelevant data about products or customers just to maintain data integrity.
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Update Anomalies:
- Redundant Updates: If the same product information is stored in multiple rows (e.g., in an orders table linked to customer data), updating the product's price would require changing it in every single place it appears. Failing to do this can lead to inconsistencies.
- Partial Updates: If a product's description needs updating, and it appears in multiple rows, there's a risk that only some of those rows will be updated, leading to data inconsistency.
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Deletion Anomalies:
- Inadvertent Data Loss: If an entry is deleted from a database that combines customer and product information, related data might be inadvertently lost. For instance, deleting a customer’s record could remove all their order history, leading to loss of critical information.
- Loss of Referential Integrity: If a product entry is removed while it is still being referenced in order entries, this can create orphaned records that lack proper associations.
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Data Redundancy:
- Increased Storage Costs: Storing duplicate data across tables can lead to significant data bloat, which would increase the overall storage requirements and affect performance.
- Inconsistency: Different entries for the same product or customer can lead to conflicting information, making it difficult to determine the true state of data (e.g., price or description).
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Data Integrity Issues:
- Violation of Business Rules: Without normalization, it may become difficult to enforce certain business rules (e.g., a product should not be assigned to multiple categories unless there's a specific way to handle that).
- Compromised Relationships: The ability to maintain correct relationships between entities (like customers, orders, and products) is typically weakened in an unnormalized structure, leading to improper joins and queries.
In summary, without normalization, the Quick Cart database could suffer from various anomalies leading to data integrity issues, increased redundancy, inefficiencies, and potential loss of valuable information. To mitigate these risks, it is important to implement normalization principles in database design.