What type of function is created with a return type of BIGINT?

A function with a return type of BIGINT is classified as a scalar function. Scalar functions operate on a single value (or a set of values) and return a single value as the result. In this case, since the return type is a BIGINT, which represents a large integer, it indicates that the function processes input data and produces an individual numerical output.

Scalar functions are commonly used in various database operations, including calculations, data conversions, and data manipulations, which often yield a single result for a specific input. Therefore, the nature of scalar functions aligns perfectly with the characteristics of the BIGINT return type.

In contrast, table functions return a table as their result, which could involve multiple rows and columns, thus not fitting the definition when returning a single BIGINT value. Window functions perform calculations across a set of table rows related to the current row, focusing on analytical processes rather than returning a single value. SQL functions encompass a wide range of capabilities, including both scalar and table functions, but the specificity of returning a BIGINT is not inherently indicative of an SQL function type alone, making scalar functions the most appropriate classification.