diff --git a/scripts/convert_db_to_v2 b/scripts/convert_db_to_v2
index efca034..98b1b27 100644
--- a/scripts/convert_db_to_v2
+++ b/scripts/convert_db_to_v2
@@ -24,7 +24,7 @@ my $ca = Simba::CA->new({
 
 my $dbh = $ca->{dbh};
 
-$dbh->{mysql_use_result} = 1;	# fetch row by row, not all at once
+#  $dbh->{mysql_use_result} = 1;	# fetch row by row, not all at once
 
 $dbh->do(q{
 	    create table versions2 (
@@ -60,7 +60,15 @@ $dbh->do(q{
 	    ) ENGINE=MyISAM DEFAULT CHARSET=utf8;
           });
 
-my $sth_select = $dbh->prepare("select * from versions");
+# mysql doesn't support nested commands,
+# so we need to read a chunk of data from versions,
+# insert it into versions2 and instances,
+# then read the next chunk ...
+
+my $chunk_size = 1_000_000;
+my $max_version_id = $dbh->selectrow_array("select max(id) from versions");
+
+my $sth_select = $dbh->prepare("select * from versions where id >= ? and id < ?");
 
 my @version2_fields = qw(
 			  file_type
@@ -96,24 +104,31 @@ my $sth_ins_instances
 	      session,
 	      version
 	    )
-	    values(?, ?, ?, ?, ?, ?)
+	    values(?, ?, ?, ?, ?, ?, ?)
 	 }
       );
 
-$sth_select->execute();
 my %versions2;
-while(my $r = $sth_select->fetchrow_hashref) {
-    my $key = join($;, map((defined $_ ? $_ : ''),
-			   @{$r}{@version2_fields}
-			  )
-                  );
-    my $version2_id;
-    if ($versions2{$key}) {
-	$version2_id = $versions2{$key};
-    } else {
-	$sth_ins_versions2->execute(@{$r}{@version2_fields});
-	$version2_id = $sth_ins_versions2->{mysql_insertid};
-	$versions2{$key} = $version2_id;
+for (my $version_id = 0; $version_id <= $max_version_id; $version_id += $chunk_size) {
+    print time - $^T, " ", $version_id, " ", scalar keys %versions2, "\n";
+    $sth_select->execute($version_id, $version_id + $chunk_size);
+    while(my $r = $sth_select->fetchrow_hashref) {
+        my $key = join($;, map((defined $_ ? $_ : ''),
+                               @{$r}{@version2_fields}
+                              )
+                      );
+        my $version2_id;
+        if ($versions2{$key}) {
+            $version2_id = $versions2{$key};
+        } else {
+            $sth_ins_versions2->execute(@{$r}{@version2_fields});
+            $version2_id = $sth_ins_versions2->{mysql_insertid};
+            $versions2{$key} = $version2_id;
+        }
+        $sth_ins_instances->execute(@{$r}{qw(id file file_id date online session)}, $version2_id);
     }
-    $sth_ins_instances->execute(@{$r}{qw(id file file_id date online session)}, $version2_id);
 }
+print time - $^T, " ", $max_version_id, " ", scalar keys %versions2, "\n";
+
+
+# vim: tw=132 expandtab sw=4 ts=8