ST_SummaryStats syntax, parameters, and examples for RDS-PolarDB(PolarDB)-阿里云帮助中心

Calculates the statistics of a specified set of bands of a raster object.

Syntax

raster ST_SummaryStats(raster raster_obj)
raster ST_SummaryStats(raster raster_obj, cstring statsOption)
raster ST_SummaryStats(raster raster_obj,
                       cstring bands,
                       cstring statsOption)

Parameters

Parameter	Description
raster_obj	The raster object.
bands	The specified band numbers. Band numbers start from 0. The format is `'0'` , `'1-3'` , or `'1,2,3'` .
statsOptions	The JSON string of statistics options.

statsOptions is used to specify the statistics parameters. The parameters are as follows:

Parameter	Description	Type	Format	Default value	Description details
approx	Specifies whether to use sampling to calculate statistics.	boolean	None	true	true: Statistics are calculated by sampling. The results may be inaccurate. false: All statistics are calculated.

Example

Calculate the statistics of a specified set of bands of a raster object.

UPDATE raster_obj SET raster_obj=ST_SummaryStats(raster_obj) WHERE id = 1;
UPDATE rast SET rast=ST_SummaryStats(rast,'0-2','{"approx":false}') WHERE id = 1;
UPDATE rast SET rast=ST_SummaryStats(rast,'{"approx":false}') WHERE id = 1;