Set a specific database to log_statement='ddl' but others to be log_statement='all'

I have a Postgresql cluster with master and multiple slaves running on version 9.6. I'm trying to adjust the log_statement from all to ddl on specific databases (i.e. postgresql.conf has log_statement='all' but I need a couple of databases set to log_statement='ddl').

etx_ecom=# ALTER DATABASE etx_ecom SET log_statement='ddl';
ALTER DATABASE
etx_ecom=# show log_statement;
 log_statement
---------------
 all
(1 row)

etx_ecom=# INSERT into card_type VALUES('Q','TEST');
INSERT 0 1

etx_ecom=#  

Feb 16 10:56:11 db1 postgres[21682]: [3602-1] <myusername@[local]->etx_ecom> LOG:  statement: INSERT into card_type VALUES('Q','TEST');

Why doesn't the Alter Database work?

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