To deal with multiple rasters loaded to a table in a database (can be PostGIS or Oracle, example is Oracle), you can use a TILEINDEX in MapServer.

Database TILEINDEXes are a little odd in MapServer, they require 2 separate layers, a TILEINDEX layer and a RASTER layer that refers to the TILEINDEX layer.

In Oracle, you'll want to create the TILEINDEX as a view to the GEORASTER table of interest.

{{{create or replace view my_raster_tindex as select some_attribute, 'geor: user/pass@tns, raster_table_DATA,'||r.raster.rasterid location, R.RASTER.spatialextent shape from rasters_table r;}}}

This view will then be used for the TILEINDEX layer

{{{
LAYER
  name raster_tindex
  TYPE polygon
  PROJECTION
    "init=epsg:xxxx"
  END
  CONNECTIONTYPE ORACLESPATIAL
  CONNECTION user/pass@tns'
  DATA "shape from my_raster_tindex using srid xxxx"
END
}}}

Then you add a second layer that is the actual RASTER layer

{{{
LAYER
  name db_raster_layer
  TYPE RASTER
  PROJECTION
    "init=epsg:xxxx"
  END
  TILEINDEX "raster_tindex"   #THIS NAME MUST MATCH THE TILEINDEX LAYER NAME
  TILEITEM "location"   #not actually needed if column is named location
  STATUS OFF
  OFFSITE 0 0 0
END
}}}

One last piece that is needed is to set the SHAPEPATH to null so that the paths to the raster files are treated as database connections and not files.

Add
{{{
SHAPEPATH ""
}}}