Re: Minimal logical decoding on standbys

make -C src/test/recovery/ check PROVE_TESTS=t/018_standby_logical_decoding_xmins.pl
#   Failed test 'physical catalog_xmin not null'
#   at t/018_standby_logical_decoding_xmins.pl line 120.
#          got: ''
#     expected: anything else

#   Failed test 'physical catalog_xmin not null'
#   at t/018_standby_logical_decoding_xmins.pl line 141.
#          got: ''
#     expected: anything else

#   Failed test 'physical catalog_xmin not null'
#   at t/018_standby_logical_decoding_xmins.pl line 159.
#          got: ''
#     expected: anything else
t/018_standby_logical_decoding_xmins.pl .. 20/27 # poll_query_until timed out executing this query:
# 

Physical catalog_xmin is NULL on master after logical slot creation on standby .

Due to this below command in the test fails with syntax error as it constructs the SQL query using catalog_xmin value 

obtained above:

# SELECT catalog_xmin::varchar::int >
# FROM pg_catalog.pg_replication_slots
# WHERE slot_name = 'master_physical';
#
# expecting this output:
# t
# last actual query output:
#
# with stderr:
# ERROR:  syntax error at or near "FROM"
# LINE 3:   FROM pg_catalog.pg_replication_slots