PostGRID do not allow to specify the band index 3 for a format if the band indexes 1 and 2 are not also defined

In a PostGRID database, it is impossible to specify in SampleDimensions a band that have an index like 3, if the band indexes 1 and 2 have not been defined, for the same format.

The needs is to be able to display only a specific band into a multi band data. That requires several layers, and for each a different format with different SampleDimensions, matching the band we want to extract.