Area Planned Targets

What Are They?

Area Planned Targets are integer values which are specified for a given epi week and geo entity. These values are (typically) entered into the system at the beginning of a transmission season and they provide a general planning goal for a given area. In the system they are recorded in the weekly_target table, which includes a column for every epi week (1 through 53).

How Are They Calculated?

Area Planned Targets must be aggregated with a rollup. If the IRSQB detects that area planned targets have been included, it creates a new (inner) instance of the IRS QB which calculates the targets and is wrapped in the original query and joined at the end. Creating a new IRSQB implies a new set of WITH views. These WITH views are not used to calculate the area planned target (that column is set to NULL) as you may expect, instead they produce a table (sprayView) which includes the correct result set (the right number of rows, and data in all columns except area planned target). This table is then populated with the area planned targets via another SELECT which invokes the custom SQL function get_area_spray_target_by_id_and_tar. This SQL function performs a recursive rollup by returning to the original weekly_target table, caching the results of previously calculated values.