Why the Aversion to SQL Cursors?

SQL Cursors: Understanding the Misconceptions

Many developers harbor a strong aversion to SQL cursors, often to the point of phobia. This often leads to unnecessarily complex solutions, like recursive CTEs, even when a simple cursor would be more efficient. This prejudice stems primarily from two sources:

Performance Myths: The perceived performance penalty of cursors is a major concern. While cursors do introduce some API overhead, it's crucial to remember that RDBMS systems themselves utilize cursors internally for operations like CREATE TABLE and INSERT.

Misapplication and Misunderstanding: The inefficient use of cursors, especially when set-based operations would suffice, has fueled the negative perception. Poorly written cursor code can indeed be problematic, but this doesn't invalidate the tool itself.

However, dismissing cursors entirely is unwarranted. They remain a valuable tool in specific scenarios:

Processing Massive Datasets: When dealing with datasets too large to fit in memory, cursors offer a practical method for row-by-row processing.

Complex Data Manipulation: Cursors provide the flexibility to iterate through results, apply custom logic, and make dynamic decisions – capabilities often beyond the reach of standard SQL.

In Summary:

While unnecessary cursor usage should be avoided, the blanket condemnation is unjustified. Understanding their strengths and weaknesses allows developers to utilize cursors effectively when appropriate, overcoming complex data handling challenges.

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