TT#71209 Add exceptions to compare db tool

Sometimes there is divergence in schemes which are inevitable or
harmless.

So add exceptions' list which is easy to maintain. The format is the
following:
=================================
<element-type>/<schema-name>/<element-name>/<element-attribute>
Where:
  element-type - tables, columns, views, etc
  schema-name  - name of the schema
  element-name - name of the element (table, index, etc)
=================================

F.e.:
  views/ldap/ldap_entries/view_definition
For columns columns/<schema-name>/<table-name>_<column-name>
  columns/billing/table1_column1/is_nullable

Add 1st exception from TT#74728. The reason of this diff is that view
was created without schema name on sp1 but the replication statement was
written with schema name.

Change-Id: I29dd109cefb560fe89d92a430cd6522e4513f7d5

helper/compare_dbs.pl

@@ -8,6 +8,22 @@ use Data::Compare;
 use Getopt::Long;
 use Carp;
 
+# Format: <element-type>/<schema-name>/<element-name>/<element-attribute>
+# Where:
+#   element-type - tables, columns, views, etc
+#   schema-name  - name of the schema
+#   element-name - name of the element (table, index, etc)
+#   element-attribute - engine for the table, is_nullable for the column, etc
+# F.e.:
+#   views/ldap/ldap_entries/view_definition
+# For columns: columns/<schema-name>/<table-name>_<column-name>
+#   columns/billing/table1_column1/is_nullable
+my @diff_exceptions = qw(
+    views/ldap/ldap_entries/view_definition
+);
+my @missing_sp1_exceptions = qw();
+my @missing_sp2_exceptions = qw();
+
 my $credentials_file = '/etc/mysql/sipwise_extra.cnf';
 my $argv = {
     formatter => '',
@@ -216,16 +232,39 @@ __USAGE__
     return 1;
 }
 
+sub is_exception {
+    my ($exceptions, $type, $schema, $element, $attr) = @_;
+
+    $attr //= '';
+    foreach my $exception (@{$exceptions}) {
+        # 'views/ldap/ldap_entries/view_definition'
+        my ($e_type, $e_schema, $e_element, $e_attr) = split( /\//, $exception );
+        $e_attr //= '';
+        if (    lc($element) eq lc($e_element)
+            and lc($type)    eq lc($e_type)
+            and lc($schema)  eq lc($e_schema)
+            and lc($attr)    eq lc($e_attr) )
+        {
+            print {*STDERR} "Exception found: $e_type/$e_schema/$e_element/$e_attr\n";
+            return 1;
+        }
+    }
+
+    return 0;
+}
+
 sub print_diff {
     my ($obj1, $obj2, $object_name, $result, $schema) = @_;
 
     foreach my $key ( sort( keys( %{$obj1} ) ) ) {
         unless ( exists($obj2->{$key}) ) {
+            next if ( is_exception(\@missing_sp2_exceptions, $object_name, $schema, $key) );
             push( @{$result}, "Schema $schema, $object_name element: $key is missing in Schema2" );
             next;
         }
         foreach my $c_name ( sort( keys( %{ $obj1->{$key} } ) ) ) {
             unless ( exists($obj2->{$key}->{$c_name}) ) {
+                next if ( is_exception(\@missing_sp2_exceptions, $object_name, $schema, $key, $c_name) );
                 push( @{$result}, "Schema $schema, $object_name element: $key.$c_name is missing in Schema2" );
                 next;
             }
@@ -237,6 +276,7 @@ sub print_diff {
             $obj2->{$key}->{$c_name} = 'NULL' if ( ! defined($obj2->{$key}->{$c_name}) );
 
             if ( $obj1->{$key}->{$c_name} ne $obj2->{$key}->{$c_name} ) {
+                next if ( is_exception(\@diff_exceptions, $object_name, $schema, $key, $c_name) );
                 push( @{$result}, "Schema $schema, $object_name elements: $key.$c_name are not equal:\n  ---\n"
                   . "  Schema1: $obj1->{$key}->{$c_name}\n"
                   . "  Schema2: $obj2->{$key}->{$c_name}" );
@@ -246,11 +286,13 @@ sub print_diff {
 
     foreach my $key ( sort( keys( %{$obj2} ) ) ) {
         unless ( exists($obj1->{$key}) ) {
+            next if ( is_exception(\@missing_sp1_exceptions, $object_name, $schema, $key) );
             push( @{$result}, "Schema $schema, $object_name element: $key is missing in Schema1" );
             next;
         }
         foreach my $c_name ( sort( keys( %{ $obj2->{$key} } ) ) ) {
             unless ( exists($obj1->{$key}->{$c_name}) ) {
+                next if ( is_exception(\@missing_sp1_exceptions, $object_name, $schema, $key, $c_name) );
                 push( @{$result}, "Schema $schema, $object_name element: $key.$c_name is missing in Schema1" );
                 next;
             }