2

If you create a series of circles/buffers in QGIS, what type of geometry do they go into PostGIS as?

  • do you need to keep each buffer or can you dissolve the edges? polygon is probably the correct geometry for further spatial analysis. – Mapperz Jan 31 '17 at 15:44
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A simple SELECT ST_Buffer(ST_MakePoint(0, 0), 1) will return a POLYGON with 32 sides, or a triacontadigon. If you wan't more or less sides, you can specify num_seg_quarter_circle in ST_Buffer (the default is 8). A series of unioned POLYGONS may result in a MULTIPOLYGON.

If you really need a circle or curved geometry, you can investigate ST_LineToCurve, however these types of geometry often have poor or limited support, so I recommend avoiding this.

2

Polygon.

Or.

MultiPolygon.

Depends on the input.

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