diff --git a/share/patch_postgresql_db_zonemaster_backend_ver_7.0.0.pl b/share/patch_postgresql_db_zonemaster_backend_ver_7.0.0.pl
index 67571864c..147e1394f 100644
--- a/share/patch_postgresql_db_zonemaster_backend_ver_7.0.0.pl
+++ b/share/patch_postgresql_db_zonemaster_backend_ver_7.0.0.pl
@@ -1,5 +1,7 @@
 use strict;
 use warnings;
+use JSON::PP;
+use Encode;
 
 use DBI qw(:utils);
 
@@ -10,69 +12,29 @@
 if ( $config->DB_engine ne 'PostgreSQL' ) {
     die "The configuration file does not contain the PostgreSQL backend";
 }
-my $dbh = Zonemaster::Backend::DB::PostgreSQL->from_config( $config )->dbh;
+my $db = Zonemaster::Backend::DB::PostgreSQL->from_config( $config );
+my $dbh = $db->dbh;
+
 
 sub patch_db {
+    my $sth1 = $dbh->prepare('SELECT id, params from test_results', undef);
+    $sth1->execute;
+    while ( my $row = $sth1->fetchrow_hashref ) {
+        my $id = $row->{id};
+        my $raw_params;
 
-    ####################################################################
-    # TEST RESULTS
-    ####################################################################
-    eval {
-        $dbh->do( 'ALTER TABLE test_results ADD COLUMN undelegated integer NOT NULL DEFAULT 0' );
-    };
-    if ($@) {
-        print "Error while changing DB schema:  " . $@;
-    }
+        if (utf8::is_utf8($row->{params}) ) {
+            $raw_params = decode_json( encode_utf8 ( $row->{params} ) );
+        } else {
+            $raw_params = decode_json( $row->{params} );
+        }
 
-    $dbh->do( qq[
-update test_results set undelegated = test_results_undelegated.undelegated_bool::int
-from (
-    select
-        test_results.id,
-        (
-            case when ds_filled.ds_filled is null then false else ds_filled.ds_filled end
-            or
-            case when ns_filled.ns_filled is null then false else ns_filled.ns_filled end
-        ) as undelegated_bool
-    from test_results
-    left join (
-        select
-            count(*) > 0 as ds_filled,
-            id
-        from (
-            select
-                jd.value,
-                id
-            from
-            (
-                select json_array_elements(params->'ds_info') as ja, id
-                from test_results
-            )  as s1,
-            json_each_text(ja) as jd
-        ) as s2
-        where value is not null and value::text != ''::text
-        group by id
-    ) as ds_filled on ds_filled.id = test_results.id
-    left join (
-            select
-            count(*) > 0 as ns_filled,
-            id
-        from (
-            select
-                jd.value,
-                id
-            from
-            (
-                select json_array_elements(params->'nameservers') as ja, id
-                from test_results
-            )  as s1,
-            json_each_text(ja) as jd
-        ) as s2
-        where value is not null and value::text != ''::text
-        group by id
-    ) as ns_filled on ns_filled.id = test_results.id
-) as test_results_undelegated where test_results.id = test_results_undelegated.id;
-    ] );
+        my $ds_info_values = scalar grep !/^$/, map { values %$_ } @{$raw_params->{ds_info}};
+        my $nameservers_values = scalar grep !/^$/, map { values %$_ } @{$raw_params->{nameservers}};
+        my $undelegated = $ds_info_values > 0 || $nameservers_values > 0 || 0;
+
+        $dbh->do('UPDATE test_results SET undelegated = ? where id = ?', undef, $undelegated, $id);
+    }
 }
 
 patch_db();