Why is Using '*' in View Definitions Risky?

The Pitfalls of Using '*' in View Definition

Suppose you have constructed a view using the wildcard character '*' to select all fields from multiple underlying tables. While this approach may seem convenient initially, it can lead to several complications.

Column Name Aliasing

A primary concern with using '' is potential collisions between column names from different tables. When multiple tables are joined, columns with the same name may exist. If you use '', all of these columns will be included in the view, but they will not be aliased. This can lead to confusion and errors when querying the view, as the desired column may be ambiguous.

Implicit Column Selection

When using '', you are explicitly choosing to include all fields from the underlying tables. While this may seem like a comprehensive solution, it can be counterproductive in certain scenarios. If a query only requires a subset of the fields, using '' can result in unnecessary data retrieval and slower query execution.

Evolutionary Schema Changes

As databases evolve, schemas are subject to change, such as the addition or removal of columns. A view defined with '' will automatically adapt to these changes, which may or may not be desirable. If a query relies on specific column names, using '' can introduce unexpected results or errors when the schema changes.

Misuse in Different Contexts

Using '*' in a view can lead to misuse in different contexts. The fact that all fields are available in the view may tempt developers to use it without considering the specific requirements of their query. This can result in inefficient queries or incorrect results.

In conclusion, while using '*' to create a view may appear convenient, it is recommended to explicitly specify the desired fields to avoid complications related to column name aliasing, implicit column selection, evolutionary schema changes, and misuse in different contexts.

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