Improve error messages introduced in be87200efd and 0fdab27ad6

Author: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Discussion: https://postgr.es/m/20230411.120301.93333867350615278.horikyota.ntt@gmail.com
Discussion: https://postgr.es/m/20230412174244.6njadz4uoiez3l74@awork3.anarazel.de

src/backend/replication/logical/decode.c

@@ -177,7 +177,7 @@ xlog_decode(LogicalDecodingContext *ctx, XLogRecordBuffer *buf)
 					Assert(RecoveryInProgress());
 					ereport(ERROR,
 							(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-							 errmsg("logical decoding on a standby requires wal_level to be at least logical on the primary")));
+							 errmsg("logical decoding on standby requires wal_level >= logical on the primary")));
 				}
 				break;
 			}

src/backend/replication/logical/logical.c

@@ -137,7 +137,7 @@ CheckLogicalDecodingRequirements(void)
 		if (GetActiveWalLevelOnStandby() < WAL_LEVEL_LOGICAL)
 			ereport(ERROR,
 					(errcode(ERRCODE_OBJECT_NOT_IN_PREREQUISITE_STATE),
-					 errmsg("logical decoding on a standby requires wal_level to be at least logical on the primary")));
+					 errmsg("logical decoding on standby requires wal_level >= logical on the primary")));
 	}
 }
 

src/backend/replication/slot.c

@@ -1274,7 +1274,7 @@ ReportSlotInvalidation(ReplicationSlotInvalidationCause cause,
 			break;
 
 		case RS_INVAL_WAL_LEVEL:
-			appendStringInfo(&err_detail, _("Logical decoding on standby requires wal_level to be at least logical on the primary server"));
+			appendStringInfo(&err_detail, _("Logical decoding on standby requires wal_level >= logical on the primary server."));
 			break;
 		case RS_INVAL_NONE:
 			pg_unreachable();

src/test/recovery/t/035_standby_logical_decoding.pl

@@ -596,8 +596,8 @@ check_for_invalidation('wal_level_', $logstart, 'due to wal_level');
 check_slots_conflicting_status(1);
 
 $handle = make_slot_active($node_standby, 'wal_level_', 0, \$stdout, \$stderr);
-# We are not able to read from the slot as it requires wal_level at least logical on the primary server
-check_pg_recvlogical_stderr($handle, "logical decoding on a standby requires wal_level to be at least logical on the primary");
+# We are not able to read from the slot as it requires wal_level >= logical on the primary server
+check_pg_recvlogical_stderr($handle, "logical decoding on standby requires wal_level >= logical on the primary");
 
 # Restore primary wal_level
 $node_primary->append_conf('postgresql.conf',q[