Upgrading from PostGIS 2.1: "Error: attempt to redefine parameter "postgis.backend"
I am trying to upgrade my PostGIS database on AWS RDS, but I am getting an error when running ALTER EXTENSION postgis UPDATE, as shown below:
my_db=> alter extension postgis update;
ERROR: attempt to redefine parameter "postgis.backend"
And here is some additional information about my database:
my_db=> select distinct probin from pg_proc where probin like '%postgis%';
-[ RECORD 1 ]-----------------
probin | $libdir/rtpostgis-2.1
-[ RECORD 2 ]-----------------
probin | $libdir/postgis-2.1
my_db=> select version();
-[ RECORD 1 ]-----------------------------------------------------------------------------------------------------
version | PostgreSQL 9.5.9 on x86_64-pc-linux-gnu, compiled by gcc (GCC) 4.8.2 20140120 (Red Hat 4.8.2-16), 64-bit
my_db=> select postgis_full_version();
-[ RECORD 1 ]--------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
postgis_full_version | POSTGIS="2.1.8 r13780" GEOS="3.5.1-CAPI-1.9.1 r4246" PROJ="Rel. 4.9.2, 08 September 2015" GDAL="GDAL 1.11.5, released 2016/07/01" LIBXML="2.9.1" LIBJSON="UNKNOWN" TOPOLOGY RASTER
The closest resource I could find to address this issue was here: http://postgis.17.x6.nabble.com/postgis-backend-and-legacy-functions-td5009743.html although that issue involved referencing multiple PostGIS versions. It seems that I am getting the same error, but my error may have a different cause, because I am only referencing postgis-2.1 and rtpostgis-2.1, as shown above. Any suggestions would be appreciated.
Update
This seems to be an issue related to RDS, where after a minutes I saw that a patch is applied to RDS via the event logs. After the patch is applied, running the alter extension postgis update command successfully upgrade the PostGIS extension. Closing this question for now.
