Higher order functions are those that can accept a function as an argument or can produce a function as their output. MySQL recent addition of stored procedures and dynamic querying makes it possible to extend the DBMS features, especially for business intelligence and data warehousing. Functions that can create functions are useful to expand the language, producing complex SQL code quickly and accurately.

Some examples of what can be achieved with these kind of functions:

• global table CRC (as oposed to record CRC) for remote table comparison
• cross tabulation (pivot tables in SQL)
• data on demand from compressed storage (indexed, as opposed to non-indexed data stored by the archive engine)
• enhanced metadata queries, where records from the information schema and records from data table create customized administrative tools.

The applications are countless. The power of stored procedures, paired with dynamic queries, can give developers the ability of doubling the features of MySQL DBMS. Higher order functions and procedures are one step beyond normal stored procedures. They give developers one template to create standardized functions for similar tasks. While the basics of such discipline are better exploited in application languages (C, C++, Perl come to mind), dynamic SQL is perfectly capable of achieving important goals.