@GET
  @Path("ddl/database/{db}/table/{table}")
  @Produces(MediaType.APPLICATION_JSON)
  public Response descTable(@PathParam("db") String db,
                @PathParam("table") String table,
                @QueryParam("format") String format)
    throws HcatException, NotAuthorizedException, BusyException,
    BadParam, ExecuteException, IOException {
    verifyUser();
    verifyDdlParam(db, ":db");
    verifyDdlParam(table, ":table");

    HcatDelegator d = new HcatDelegator(appConf, execService);
    if ("extended".equals(format)) {
      return d.descExtendedTable(getDoAsUser(), db, table);
    }
    else {
      return d.descTable(getDoAsUser(), db, table, false);
    }
  }
Describe an hcat table.  This is normally a simple list of
columns (using "desc table"), but the extended format will show
more information (using "show table extended like").
hcatalog/webhcat/svr/src/main/java/org/apache/hive/hcatalog/templeton/Server.java