Advice on loading OpenTopography data into a PostGIS database apreciated

[thiemo at gelassene-pferde.biz]

thiemo at gelassene-pferde.biz escribió:
> treintaytres=> set postgis.gdal_enabled_drivers = 'ENABLE_ALL';
> SET
> treintaytres=> WITH foo AS (
>     SELECT  
> ST_AsPNG(ST_AddBand(ST_AddBand(ST_AddBand(ST_MakeEmptyRaster(2, 2,  
> 0, 0, 0.1, -0.1, 0, 0, 4326), 1, '8BUI', 1, 0), 2, '8BUI', 2, 0), 3,  
> '8BUI', 3, 0)) AS png
> ),
> bar AS (
>     SELECT 1 AS rid, ST_FromGDALRaster(png) AS rast FROM foo
>     UNION ALL
>     SELECT 2 AS rid, ST_FromGDALRaster(png, 3310) AS rast FROM foo
> )
> SELECT
>     rid,
>     ST_Metadata(rast) AS metadata,
>     ST_SummaryStats(rast, 1) AS stats1,
>     ST_SummaryStats(rast, 2) AS stats2,
>     ST_SummaryStats(rast, 3) AS stats3
> FROM bar
> ORDER BY rid;
> WARNING:  permission denied to set parameter "postgis.gdal_enabled_drivers"
> ERROR:  rt_raster_to_gdal: Could not load the output GDAL driver
> CONTEXT:  PL/pgSQL function st_aspng(raster,text[]) line 31 at RETURN

I figured out that if the executing user has the superuser privilege,  
it works; however, I am not comfortable with this. I wonder whether  
this is a must.


test_db=# alter role test_user SUPERUSER;

--

test_db=> set postgis.gdal_enabled_drivers = 'ENABLE_ALL';
SET
test_db=> WITH foo AS (
     SELECT  
ST_AsPNG(ST_AddBand(ST_AddBand(ST_AddBand(ST_MakeEmptyRaster(2, 2, 0,  
0, 0.1, -0.1, 0, 0, 4326), 1, '8BUI', 1, 0), 2, '8BUI', 2, 0), 3,  
'8BUI', 3, 0)) AS png
),
bar AS (
     SELECT 1 AS rid, ST_FromGDALRaster(png) AS rast FROM foo
     UNION ALL
     SELECT 2 AS rid, ST_FromGDALRaster(png, 3310) AS rast FROM foo
)
SELECT
     rid,
     ST_Metadata(rast) AS metadata,
     ST_SummaryStats(rast, 1) AS stats1,
     ST_SummaryStats(rast, 2) AS stats2,
     ST_SummaryStats(rast, 3) AS stats3
FROM bar
ORDER BY rid;
  rid |         metadata          |    stats1     |    stats2     |     stats3
-----+---------------------------+---------------+---------------+----------------
    1 | (0,0,2,2,1,-1,0,0,0,3)    | (4,4,1,0,1,1) | (4,8,2,0,2,2) |  
(4,12,3,0,3,3)
    2 | (0,0,2,2,1,-1,0,0,3310,3) | (4,4,1,0,1,1) | (4,8,2,0,2,2) |  
(4,12,3,0,3,3)
(2 rows)