summarystats — A composite type returned by the ST_SummaryStats and ST_SummaryStatsAgg functions.
A composite type returned by the ST_SummaryStats and ST_SummaryStatsAgg functions.
count 
								integer
							Number of pixels counted for the summary statistics.
sum 
								double precision
							Sum of all counted pixel values.
mean 
								double precision
							Arithmetic mean of all counted pixel values.
stddev 
								double precision
							Standard deviation of all counted pixel values.
min 
								double precision
							Minimum value of counted pixel values.
max 
								double precision
							Maximum value of counted pixel values.