Postgresql: Can't access to file « $libdir/postgis-2.1 » no such file or directory

Question

I guess this is a known issue but since I have used a script that removed my postgresql-9.4-postgis-2.1, I'm now unable to get rid of this SQL error under Debian.

Can't access to file « $libdir/postgis-2.1 » no such file or directory

I've done the following:

- Remove new unwanted postgresql-9.5-postgis-2.2 package installed
- Reinstalling postgresql-9.4-postgis-2.1, postgresql-9.4-postgis-scripts and postgis
- Using SQL: ALTER EXTENSION postgis UPDATE TO '2.1.4' --under postgres user
- Using SQL: ALTER EXTENSION postgis_topology UPDATE TO '2.1.4' --under postgres user

And SELECT * FROM pg_available_extensions; returns

[...]
postgis 2.1.4   2.1.4   PostGIS geometry, geography, and raster spatial types and functions.

But still this message when accessing object like tables that uses geometry type.

Any idea?

Answer 1

First run (as postgres administrator) in the database that needs it (\c your-database-name):

ALTER EXTENSION postgis UPDATE;

If this returns successfully, then check what version you have

SELECT PostGIS_Full_Version();

If however, the server returns that it cannot find the extension postgis, then run

CREATE EXTENSION postgis;
CREATE EXTENSION postgis_topology;
ALTER EXTENSION postgis UPDATE;

and again check by running

SELECT PostGIS_Full_Version();

Answer 2

Finally "solve" the issue compiling from source postgis 2.2.2 (that also requires gdal, proj4 and geos) and then issuing

CREATE EXTENSION postgis;
CREATE EXTENSION postgis_topology;

since DROP EXTENSION postgis; tells me postgis wasn't present anymore.

And finally:

ALTER EXTENSION postgis UPDATE TO '2.2.2';
ALTER EXTENSION postgis_topology UPDATE TO '2.2.2';

Got access again to my geom data and functions from PostgreSQL 9.4. It seems that compiling from source updated correctly the variable path for postgresql and installed /usr/lib/postgresql/9.4/lib/postgis-2.2.so that wasn't present anymore (for postgis-2.1.so as well), even with (re)installing from apt-get.

Hope this will help.