The (pretty old) RHEL7 jdbc connector might well be run against newer
PostgreSQL servers; newer than the system-default PostgreSQL 9.2,
especially if we consider that we are asynchronously adding new servers
into RHSCL channel.

During the lifetime of postgresql-jdbc package, PostgreSQL upstream bumped
major version from 9.6 to 10 (together with changing of the versioning
scheme), which caused troubles with the implemented server-version
comparator in pgjdbc; that code did not count with two-digit numbers in
version string.  This patch fixes the problem downstream-only way, since
backporting related upstream fixes would lead to much larger patch and
risks that something goes wrong.  We still fallback to the old comparison
method when we are not sure about the comparison (that is when isNewerOrEqual
throws some exception).

diff --git a/org/postgresql/jdbc2/AbstractJdbc2Connection.java b/org/postgresql/jdbc2/AbstractJdbc2Connection.java
index 2fb37f4..d889247 100644
--- a/org/postgresql/jdbc2/AbstractJdbc2Connection.java
+++ b/org/postgresql/jdbc2/AbstractJdbc2Connection.java
@@ -1061,14 +1061,39 @@ public abstract class AbstractJdbc2Connection implements BaseConnection
         }
     }
 
+    private static boolean
+        isNewerOrEqual(String v1, String v2)
+    {
+        Iterator<String> i1 = Arrays.asList(v1.split("\\.")).iterator();
+        Iterator<String> i2 = Arrays.asList(v2.split("\\.")).iterator();
+
+        while (true) {
+            if (!i1.hasNext())
+                return true;
+            if (!i2.hasNext())
+                return false;
+
+            int left = Integer.parseInt(i1.next());
+            int right = Integer.parseInt(i2.next());
+
+            if (right == left)
+                continue;
+
+            return right >= left;
+        }
+    }
+
     /**
      * Is the server we are connected to running at least this version?
-     * This comparison method will fail whenever a major or minor version
-     * goes to two digits (10.3.0) or (7.10.1).
      */
     public boolean haveMinimumServerVersion(String ver)
     {
-        return (dbVersionNumber.compareTo(ver) >= 0);
+        try {
+            return isNewerOrEqual(ver, dbVersionNumber);
+        }
+        catch (Exception e) {
+            return (dbVersionNumber.compareTo(ver) >= 0);
+        }
     }
 
     /*