Steps to reproduce:

1. Install timescaledb extension from official postgresql repo instead of timescaledb provided
2. try to use compression

    16737:20220314:111150.042 [Z3005] query failed: [0] PGRES_FATAL_ERROR:ERROR:  functionality not supported under the current "apache" license
   HINT:  Upgrade your license to 'timescale' to use this free community feature.
    [alter table history set (timescaledb.compress,timescaledb.compress_segmentby='itemid',timescaledb.compress_orderby='clock,ns')]
    16737:20220314:111150.043 [Z3005] query failed: [0] PGRES_FATAL_ERROR:ERROR:  function "add_compression_policy" is not supported under the current "apache" license
   HINT:  Upgrade your license to 'timescale' to use this free community feature.
    [select add_compression_policy('history', integer '612000')]
    16737:20220314:111150.043 failed to add compression policy to table 'history'
   

This is correct, but in documentation where is no information about TSL licensed library requirements, all community packages are provided with only Apache licensed module.

-rwxr-xr-x  1 root root 6007552 Mar 14 12:31 timescaledb-2.6.0.so

# not provided by default with community packages:
-rwxr-xr-x  1 root root 6379480 Mar 14 12:31 timescaledb-tsl-2.6.0.so

So the following will fail with:

ALTER SYSTEM SET timescaledb.license = 'timescale';

 ERROR: could not access file "$libdir/timescaledb-tsl-2.6.0": No such file or directory

https://www.zabbix.com/documentation/current/en/manual/appendix/install/timescaledb#timescaledb-compression

Expected:

1. Fatal error is not handled like fatal and frontend keeps "thinking" that compression can be used;
2. Not all timescaledb library packages are made equally, community based versions from official postgresql repo or distro version like provided in SUSE/openSUSE are build only with Apache licenses - so it's good to mention in the docs to have full featured TSDB version (without APACHE_ONLY=1 build);

<mprihodko> Documentation changes can be combined with ZBX-20878