Calculate checksums for individual tables or whole databases, to allow quick comparison

misc-scripts/db/fingerprint_db.pl

+use strict;
+
+use DBI;
+use Getopt::Long;
+
+my ($host, $port, $dbname, $user, $pass, @tables, $limit);
+
+GetOptions('user=s'       => \$user,
+	   'pass=s'       => \$pass,
+	   'host=s'       => \$host,
+	   'port=i'       => \$port,
+	   'dbname=s'     => \$dbname,
+	   'tables=s'     => \@tables,
+	   'limit=s'      => \$limit,
+	   'help'         => sub { usage(); exit(0); });
+
+@tables = split(/,/,join(',',@tables));
+
+if (!$user || !$host || !$dbname) {
+
+  usage();
+  exit(1);
+
+}
+
+my $dbi = DBI->connect( "DBI:mysql:host=$host:port=$port;database=$dbname", $user, $pass,
+			{'RaiseError' => 1}) || die "Can't connect to database\n";
+
+# use all if not specified
+if (!@tables) {
+  my $sth = $dbi->prepare("SHOW TABLES;");
+  $sth->execute();
+  foreach my $row (@{$sth->fetchall_arrayref()}) {
+    push @tables, $row->[0];
+  }
+}
+
+print "Table\tDescription checksum\tData checksum\n";
+
+foreach my $table (@tables) {
+
+  print $table . "\t";
+
+  my $passopt = $pass ? "-p$pass" : "";
+
+  my $key_sth = $dbi->prepare("SHOW INDEX FROM $table");
+  $key_sth->execute();
+  my ($primary_key, $first_col);
+  while (my @cols = $key_sth->fetchrow()) {
+    $first_col = $cols[4];
+    if ($cols[2] eq "PRIMARY") {
+      $primary_key = $cols[4];
+      last;
+    }
+  }
+
+  my $key = $primary_key;;
+  if (!$key) {
+    # print "Can't get primary key for table $table, using $first_col as key\n";
+    $key = $first_col;
+  }
+
+  # description - note use of tr -d to strip newline
+  system ("mysql -u $user -h $host $passopt -P $port -e \'DESC $table\' $dbname | md5sum | tr -d '\n'");
+
+  print "\t";
+
+  # data
+  my $limitclause = $limit ? " LIMIT $limit" : "";
+  my $cmd = "\'SELECT * FROM $table ORDER BY $key $limitclause;desc $table;\'";
+  system ("mysql -u $user -h $host $passopt -P $port -e $cmd $dbname | md5sum");
+
+}
+
+
+
+sub usage {
+
+  print << "EOF";
+
+  fingerprint_db.pl -user {user} -pass {password} -host {host} -port {port} -dbname {database} -tables {tables} -limit {rows}
+
+  Generates an MD5 checksum for the description and data of all or some tables of a database.
+
+  Argument to tables may be comma-separated, or multiple -tables arguments may be used.
+  If no -tables argument is given all tables are analysed.
+
+  Use -limit to limit the number of rows the comparison is based on; less accurate but faster for large tables.
+
+  A single fingerprint for the whole database can be computed by piping the output of this script into md5sum.
+
+EOF
+
+}