Обсуждение: [HACKERS] wal_level > WAL_LEVEL_LOGICAL

As per my understabding, current postgres server supports only three
values for wal_level i.e. 'minimal' , 'replica' or 'logical'. But
following error message brought to notice that there are various code
spots that try to look for wal_level >= WAL_LEVEL_LOGICAL:
 select * from pg_create_logical_replication_slot('regression_slot',
'test_decoding'); ERROR:  logical decoding requires wal_level >= logical

The code locations that look for/expect wal_level > WAL_LEVEL_LOGICAL are:
heapam.c         7690 * This is only used in wal_level >=
WAL_LEVEL_LOGICAL, and only for cataloglogical.c           83 errmsg("logical decoding requires wal_level >=
logical")));standby.c        LogStandbySnapshot               950 if (wal_level
>= WAL_LEVEL_LOGICAL)xlog.h           XLogLogicalInfoActive            162 #define
XLogLogicalInfoActive() (wal_level >= WAL_LEVEL_LOGICAL)

Since postgres does not allow wal_level > WAL_LEVEL_LOGICAL, the above
code locations should be modified like:
s/>=/=

Thoughts/Suggestions?

Regards,
Neha

On Mon, May 22, 2017 at 9:08 AM, Neha Khatri <nehakhatri5@gmail.com> wrote:
> As per my understabding, current postgres server supports only three
> values for wal_level i.e. 'minimal' , 'replica' or 'logical'. But
> following error message brought to notice that there are various code
> spots that try to look for wal_level >= WAL_LEVEL_LOGICAL:

I suspect that this was intended as future-proofing.  I think it's
actually very reasonable to write the internal tests that way, but it
does seem strange that it's crept into the user-visible error
messages.

-- 
Robert Haas
EnterpriseDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company