Outputs are specified in the startVisitOutput, startVisitResource, startVisitInput, and startVisitMarket methods of xml_db_outputter.cpp.
1: There is a long list of standard queries that report quantity outputs. The "physical output" query listed above will report all outputs at the technology level. The "inputs" query listed above will report all inputs to each technology. The other queries filter or aggregate those outputs. For example, the "outputs by sector" query aggregates physical-output to the sector level; the "elec gen by gen tech" query filters the physical-output for electricity generating technologies. The "primary energy consumption by region (direct equivalent)" aggregates all energy-related inputs, providing a total energy consumption by fuel, region, and year. 2: Outputs are reported at the regional resolution of the sector. See Regional Resolution 3: Units vary. In general, energy-related outputs are reported in EJ/yr, agricultural outputs are in Mt/yr, forestry outputs are in million m3/yr, and water outputs are in km3/yr. 4: Supply and demand can be reported by market. The market name contains both region and commodity information. For example, globalcrude oil is the globally traded crude oil market and USACorn is Corn market in the USA. Some markets will have both a global and a regional supply or demand.