Issues with setting a global setting in PostgreSQL 9.5/PostGIS2.2

Question

I am trying to set a global setting/GUC variable postgis.gdal_enabled_drivers from the PostGIS extension for a while. I am a non-admin user but can ask admin to change settings if needed. But I tried several different methods following the instructions but none worked.

1. I tried the old fashion way to change environmental variables. I had the following added to /etc/environment:

   POSTGIS_ENABLE_OUTDB_RASTERS=1
   POSTGIS_GDAL_ENABLED_DRIVERS=ENABLE_ALL
   

so that echo $POSTGIS_GDAL_ENABLED_DRIVERS returns ENABLE_ALL

Now, in my non-admin PostreSQL account,

SELECT short_name, long_name FROM ST_GdalDrivers();

returns 0 rows, meaning no GDAL drivers are enabled.

2. I also tried to have postgres to:

   ALTER SYSTEM SET postgis.gdal_enabled_drivers TO 'ENABLE_ALL';
   

but I got an error:

ERROR:  unrecognized configuration parameter "postgis.gdal_enabled_drivers"

3. I tried to:

   ALTER DATABASE my_db SET postgis.gdal_enabled_drivers TO 'ENABLE_ALL';
   

but I got:

ERROR:  permission denied to set parameter "postgis.gdal_enabled_drivers"

In sum, I can ask admin to change some settings once as in methods 1 and 2, but not every time e.g. when I do a full database restore (method 3).

My question is:

How can I make the above methods work?

FYI, my PostgreSQL version is 9.5.1, OS is Lubuntu 16.04 beta

    postgis_version            
---------------------------------------
 2.2 USE_GEOS=1 USE_PROJ=1 USE_STATS=1

In method 3, I can use postgres to ALTER DATABASE but I can't ask amin to do that every time I restore db, where I do something like:

dropdb my_db && createdb -T template my_db $$ psql < my_pg_dump_file

Answer 1

Edit the /etc/postgresql/9.x/main/environment file and set following environment variables POSTGIS_GDAL_ENABLED_DRIVERS=ENABLE_ALL POSTGIS_ENABLE_OUTDB_RASTERS=1. Restart then the server.

Answer 2

Debugging first, do this.

1. SET postgis.gdal_enabled_drivers = 'ENABLE_ALL';
2. SELECT * FROM ST_GdalDrivers();

If this returns nothing, you've got larger issues. Did you install from the Ubuntu/LUbuntu repos? Or, did you build yourself?

ALTER SYSTEM is the new method to alter the configuration file with a pseudo-sql command. If you're seeing this

ERROR: unrecognized configuration parameter "postgis.gdal_enabled_drivers"

That means that you do not have that option in your postgresql.conf. (perhaps it's commented out.) That however you can still add it the conf file manually.

A configuration option to set the enabled GDAL drivers in the PostGIS environment. Affects the GDAL configuration variable GDAL_SKIP. This option can be set in PostgreSQL's configuration file: postgresql.conf. It can also be set by connection or transaction.

ALTER SYSTEM SET postgis.gdal_enabled_drivers TO 'GTiff PNG JPEG';

or to whatever you want. I would not set the environment. Instead, just put this in your /etc/postgresql/9.5/main/postgresql.conf

postgis.gdal_enabled_drivers = 'ENABLE_ALL';

Which is essentially the same as what the docs say,

SET postgis.gdal_enabled_drivers = 'ENABLE_ALL';