## 9.25. Set Returning Functions[]() This section describes functions that possibly return more than one row. The most widely used functions in this class are series generating functions, as detailed in [Table 9.63](functions-srf.html#FUNCTIONS-SRF-SERIES) and [Table 9.64](functions-srf.html#FUNCTIONS-SRF-SUBSCRIPTS). Other, more specialized set-returning functions are described elsewhere in this manual. See [Section 7.2.1.4](queries-table-expressions.html#QUERIES-TABLEFUNCTIONS) for ways to combine multiple set-returning functions.**Table 9.63. Series Generating Functions**| Function<br/><br/> Description ||-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------||[]()`generate_series` ( *`start`*`integer`, *`stop`*`integer` [, *`step`*`integer` ] ) → `setof integer`<br/><br/>`generate_series` ( *`start`*`bigint`, *`stop`*`bigint` [, *`step`*`bigint` ] ) → `setof bigint`<br/><br/>`generate_series` ( *`start`*`numeric`, *`stop`*`numeric` [, *`step`*`numeric` ] ) → `setof numeric`<br/><br/> Generates a series of values from *`start`* to *`stop`*, with a step size of *`step`*. *`step`* defaults to 1.|| `generate_series` ( *`start`*`timestamp`, *`stop`*`timestamp`, *`step`*`interval` ) → `setof timestamp`<br/><br/>`generate_series` ( *`start`*`timestamp with time zone`, *`stop`*`timestamp with time zone`, *`step`*`interval` ) → `setof timestamp with time zone`<br/><br/> Generates a series of values from *`start`* to *`stop`*, with a step size of *`step`*. | When *`step`* is positive, zero rows are returned if *`start`* is greater than *`stop`*. Conversely, when *`step`* is negative, zero rows are returned if *`start`* is less than *`stop`*. Zero rows are also returned if any input is `NULL`. It is an error for *`step`* to be zero. Some examples follow:```SELECT * FROM generate_series(2,4); generate_series
