Estimate the size of the spatial column

The size of a spatial column depends on the points per feature, and coordinate factor, and the annotation size.

Estimate the size of the spatial column using the formula:

spatial column size = (average points per feature * coordinate factor) 
+ annotation size

The average points per feature is the sum of all coordinate points required to render the features stored in a spatial table divided by the number of rows in the table. If the sum of all coordinates is difficult to obtain, use the approximations of the average number of points per feature for each data type in the table.

The collection data types (MultiPoints, MultiLineStrings, and MultiPolygons) are difficult to estimate. The numbers shown in the table are based on the types of data sets that these data types are most often applied to: broadcast patterns for MultiPoints, stream networks for MultiLineStrings, and island topology for MultiPolygons.


Data type	Average points per feature
Point	1
LineString (urban)	5
LineString (rural)	50
Polygon (urban)	7
Polygon (rural)	150
MultiPoint	50
MultiLineString	250
MultiPolygon	1000

The coordinate factor is based on the dimensions of the coordinates stored by the spatial column. Select the coordinate factor from the table below.


Coordinate type	Coordinate factor
XY	4.8
XYZ	7.2
XY and measures	7.2
XYZ and measures	9.6

If your layer includes annotation, set the annotation size to 300 bytes (this is the average space required to store most annotation). This includes the space required to store text, placement geometry, lead line geometry, and various attributes describing the annotation's size and font.