I am using ArcMap 10.4.
I have an attribute table of shapefile with more than 20 millions rows stored in gdb. That table has a column with postcodes (that are often repeated) and column with values. I want to sum all values that refer to each unique postcode and for that I used Summary Statistics toolbox. But something went wrong. As result I have values for 2426 postcodes, when I know that there are 4709. Half of the values are missing in statistics table.
Does anybody know how to solve this or might know what has happened?