Hfrhyu

The following is a JSON representation of an large array of planar spatial surfaces.

"type":"Feature",
 "geometry":
 "type":"MultiPolygon",
 "coordinates":
 [[[[17.7529,-31.146],[17.9742,-30.9097],[17.9783,-30.7836],[18.0728,-30.7795],[18.1533,-30.8411],[18.245,-30.8067],[18.3456,-30.6569],[18.3967,-30.5128],[18.5503,-30.4289],[18.6436,-30.5436],[18.7428,-30.5625],[18.7678,-30.6539],[18.8481,-30.7147],[18.9386,-30.7242],[18.9667,-30.9292],[18.8858,-31.03],[18.9364,-31.1072],[18.9269,-31.2161],[19.0139,-31.3694],[19.0639,-31.5083],[19.0869,-31.7522],[19.0311,-31.8328],[19.0883,-31.8969],[19.293,-31.9775],[19.3217,-32.0317],[19.4822,-32.0814],[19.4961,-32.2456],[19.3989,-32.2922],[19.4917,-32.4711],[19.4728,-32.5836],[19.5953,-32.6236],[19.605,-32.4908],[19.7944,-32.387],[19.9222,-32.3739],[20.0386,-32.2497],[20.1644,-32.1758],[20.2178,-32.2306],[20.1494,-32.3728],[20.0647,-32.4389],[20.1761,-32.7578],[20.2717,-32.7917],[20.4211,-32.9369],[20.5564,-32.8844],[20.5964,-32.9367],[20.7181,-32.9283],[20.8206,-32.8108],[20.7953,-32.6967],[20.9678,-32.6369],[21.1611,-32.613],[21.1922,-32.4592],[21.3231,-32.3736],[21.5469,-32.305],[21.5375,-32.2236],[21.7236,-32.1981],[21.8506,-32.2619],[21.9986,-32.1881],[22.0019,-32.0978],[22.1233,-32.05],[22.0636,-31.9203],[22.1653,-31.8786],[22.1711,-31.7758],[22.2914,-31.5703],[22.5922,-31.725],[22.565,-31.8005],[22.7233,-31.8022],[23.0464,-31.8853],[23.0697,-31.9767],[23.2139,-31.8681],[23.2664,-31.7425],[23.4008,-31.6814],[23.5097,-31.6994],[23.5847,-31.6544],[23.7258,-31.6589],[23.8261,-31.7256],[23.8567,-31.8233],[24.0206,-31.7281],[24.1469,-31.79],[24.1522,-31.895],[24.205,-31.9472],[24.0872,-32.0906],[24.0719,-32.1556],[23.8736,-32.2461],[23.7519,-32.1767],[23.6539,-32.2353],[23.6458,-32.3336],[23.4325,-32.3283],[23.2081,-32.4247],[23.2678,-32.5342],[23.3633,-32.8264],[23.1781,-32.7894],[23.0778,-32.8781],[22.9381,-32.9425],[22.9364,-33.0914],[22.8806,-33.1372],[22.7633,-33.3169],[22.7494,-33.4017],[22.8972,-33.4145],[23.0394,-33.3833],[23.2925,-33.3903],[23.3236,-33.432],[23.48,-33.4344],[23.5747,-33.4886],[23.655,-33.6175],[23.4125,-33.7133],[23.465,-33.7967],[23.6867,-33.8722],[23.6395,-33.9821],[23.449,-34.0051],[23.3649,-34.1051],[23.2251,-34.0871],[22.959,-34.0887],[22.9149,-34.0646],[22.564,-33.9962],[22.4851,-34.0526],[22.2371,-34.0576],[22.1232,-34.1165],[22.1135,-34.2049],[21.931,-34.2451],[21.8696,-34.364],[21.6954,-34.3957],[21.5368,-34.3568],[21.4446,-34.3682],[21.3051,-34.441],[21.0015,-34.3649],[20.8537,-34.3976],[20.8474,-34.4751],[20.6626,-34.4493],[20.5338,-34.4701],[20.4007,-34.5724],[20.0829,-34.7332],[19.9904,-34.8351],[19.8751,-34.7668],[19.6329,-34.7551],[19.4485,-34.6551],[19.354,-34.4774],[19.2713,-34.4093],[19.1226,-34.4185],[19.0376,-34.3412],[18.911,-34.3574],[18.8132,-34.1007],[18.7126,-34.0721],[18.4946,-34.0988],[18.3804,-34.2624],[18.3304,-34.024],[18.3976,-33.8993],[18.4854,-33.8415],[18.4376,-33.6929],[18.3154,-33.5096],[18.0974,-33.2301],[17.9696,-33.1376],[17.9915,-32.9965],[17.871,-32.991],[17.8957,-32.7429],[17.9796,-32.7268],[18.129,-32.7774],[18.2479,-32.6774],[18.3349,-32.4587],[18.3135,-32.3171],[18.3457,-32.281],[18.2257,-31.7507],[18.1165,-31.5829],[17.899,-31.351],[17.879,-31.2801],[17.7529,-31.146]]],[[[37.9069,-46.8996],[37.8564,-46.9683],[37.657,-46.9744],[37.5803,-46.9364],[37.6894,-46.8239],[37.8047,-46.8372],[37.9069,-46.8996]]]]
 ,
 "properties":
 "name":"Western Cape",
 "id":"ZA-WC",
 "CNTRY":"South Africa",
 "TYPE":"Province"
 ,
 "id":"ZA-WC"
,
"type":"Feature",
 "geometry":
 "type":"Polygon",
 "coordinates":
 [[[-2.1512,49.2607],[-2.1353,49.2535],[-2.1049,49.2506],[-2.1013,49.2558],[-2.0913,49.2536],[-2.0801,49.2393],[-2.0731,49.2377],[-2.0529,49.2423],[-2.0414,49.2363],[-2.0253,49.2321],[-2.024,49.2271],[-2.03,49.2163],[-2.0179,49.2003],[-2.0283,49.1982],[-2.033,49.182],[-2.0277,49.1679],[-2.0332,49.1644],[-2.054,49.17],[-2.0782,49.1635],[-2.0917,49.1751],[-2.0985,49.1779],[-2.111,49.1764],[-2.1186,49.189],[-2.1311,49.1948],[-2.1421,49.1968],[-2.1595,49.1959],[-2.1692,49.1891],[-2.1695,49.1789],[-2.175,49.1717],[-2.1887,49.1765],[-2.19,49.1835],[-2.2018,49.185],[-2.204,49.1788],[-2.2234,49.1748],[-2.2435,49.1818],[-2.2309,49.1892],[-2.2233,49.2044],[-2.2307,49.2255],[-2.2421,49.2388],[-2.2535,49.2476],[-2.2538,49.2528],[-2.2425,49.259],[-2.211,49.2549],[-2.1974,49.2495],[-2.1826,49.2495],[-2.1704,49.2539],[-2.1653,49.259],[-2.1512,49.2607]]]
 ,
 "properties":
 "name":"Jersey",
 "id":"JE",
 "TYPE":"Jersey",
 "CNTRY":"Jersey"
 ,
 "id":"JE"
,

While this documentation describes representations POLYGON and MULTIPOLYGON, how should this table should be created as the object will have coordinates, assuming using Rails' PostGIS adapter

create_table :my_spatial_table do |t|
 t.st_polygon :the_shape, , srid: -1
 [and/or]
 t.multi_polygon :the_multi_shape, srid: -1
 t.string :name
 t.string :id
 t.string :country
 t.string :type
 t.boolean :multi
 end

Intuitively, I would go with the multi_polygon allowing for records with a single polygon defined. However this appears to be at odds with the examples of text representations (logically, 2 parenthesis for polygon, 3 for multipolygon) the documentation; it appears postgresql is expecting a specific format. Naturally, this is intrinsincly linked to the import of the data.

Assuming this data is transformed into a CSV file, how should the table be created

• with 1 MULTIPOLYGON attribute , or,


• with 2 attributes, 1 MULTIPOLYGON and the other POLYGON with a boolean descriptor allowing queries to focus on one attribute of the other?

And how should the data be represented for proper digestion by PostgreSQL in the import process (parenthesis in lieu of square brackets and in relevant numbers, I assume), particluarly if one choose the single MULTIPOLYGON datatype ?