observatory-extension/doc/discovery_functions.md
2016-05-17 15:02:14 -04:00

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Discovery Functions

If you are using the discovery methods from the Data Observatory, use the following functions to retrieve boundary and measures data.

OBS_Search(search_term)

Use arbitrary text to search all available measures

Arguments

Name Description
search_term a string to search for available measures
boundary_id a string identifier for a boundary geometry (optional)

Returns

A TABLE containing the following properties

Key Description
id the unique id of the measure for use with the OBS_GetMeasure function
name the human readable name of the measure
description a brief description of the measure
aggregate sum are raw count values, median are statistical medians, average are statistical averages, undefined other (e.g. an index value)
source where the data came from (e.g. US Census Bureau)

Example

SELECT * FROM OBS_Search('home value')

OBS_GetAvailableBoundaries(point_geometry)

Returns available boundary_ids at a given point geometry.

Arguments

Name Description
point_geometry a WGS84 point geometry (e.g. the_geom)

Returns

A TABLE containing the following properties

Key Description
boundary_id a boundary identifier from the boundary ID glossary
description a brief description of the boundary dataset
time_span the timespan attached the boundary. this does not mean that the boundary is invalid outside of the timespan, but is the explicit timespan published with the geometry.

Example

SELECT * FROM OBS_GetAvailableBoundaries(CDB_LatLng(40.7, -73.9))