diff --git a/src/lib/Hydra/Helper/AddBuilds.pm b/src/lib/Hydra/Helper/AddBuilds.pm
index 3eff4f75..27e68737 100644
--- a/src/lib/Hydra/Helper/AddBuilds.pm
+++ b/src/lib/Hydra/Helper/AddBuilds.pm
@@ -6,6 +6,7 @@ use XML::Simple;
 use POSIX qw(strftime);
 use IPC::Run;
 use Nix::Store;
+use Hydra::Model::DB;
 use Hydra::Helper::Nix;
 use Digest::SHA qw(sha256_hex);
 use File::Basename;
@@ -22,7 +23,7 @@ our @EXPORT = qw(
 
 
 sub scmPath {
-    return getHydraPath . "/scm" ;
+    return Hydra::Model::DB::getHydraPath . "/scm" ;
 }
 
 
diff --git a/src/lib/Hydra/Helper/Nix.pm b/src/lib/Hydra/Helper/Nix.pm
index 07ea5858..ab87989e 100644
--- a/src/lib/Hydra/Helper/Nix.pm
+++ b/src/lib/Hydra/Helper/Nix.pm
@@ -5,23 +5,17 @@ use Exporter;
 use File::Path;
 use File::Basename;
 use Hydra::Helper::CatalystUtils;
+use Hydra::Model::DB;
 
 our @ISA = qw(Exporter);
 our @EXPORT = qw(
-    getHydraPath getHydraHome getHydraDBPath openHydraDB getHydraConf txn_do
+    getHydraHome getHydraConf txn_do
     registerRoot getGCRootsDir gcRootFor
     getPrimaryBuildsForView
     getPrimaryBuildTotal
     getViewResult getLatestSuccessfulViewResult jobsetOverview removeAsciiEscapes);
 
 
-sub getHydraPath {
-    my $dir = $ENV{"HYDRA_DATA"} || "/var/lib/hydra";
-    die "The HYDRA_DATA directory ($dir) does not exist!\n" unless -d $dir;
-    return $dir;
-}
-
-
 sub getHydraHome {
     my $dir = $ENV{"HYDRA_HOME"} or die "The HYDRA_HOME directory does not exist!\n";
     return $dir;
@@ -29,33 +23,12 @@ sub getHydraHome {
 
 
 sub getHydraConf {
-    my $conf = $ENV{"HYDRA_CONFIG"} || (getHydraPath . "/hydra.conf");
+    my $conf = $ENV{"HYDRA_CONFIG"} || (Hydra::Model::DB::getHydraPath . "/hydra.conf");
     die "The HYDRA_CONFIG file ($conf) does not exist!\n" unless -f $conf;
     return $conf;
 }
 
 
-sub getHydraDBPath {
-    my $db = $ENV{"HYDRA_DBI"};
-    if ( defined $db ) {
-      return $db ;
-    }
-    else {
-        my $path = getHydraPath . '/hydra.sqlite';
-        die "The Hydra database ($path) not exist!\n" unless -f $path;
-        return "dbi:SQLite:$path";
-    }
-}
-
-
-sub openHydraDB {
-    my $db = Hydra::Schema->connect(getHydraDBPath, "", "", {});
-    $db->storage->dbh->do("PRAGMA synchronous = OFF;")
-        if defined $ENV{'HYDRA_NO_FSYNC'};
-    return $db;
-}
-
-
 # Awful hack to handle timeouts in SQLite: just retry the transaction.
 # DBD::SQLite *has* a 30 second retry window, but apparently it
 # doesn't work.
diff --git a/src/lib/Hydra/Model/DB.pm b/src/lib/Hydra/Model/DB.pm
index eb5f5168..c76ce37c 100644
--- a/src/lib/Hydra/Model/DB.pm
+++ b/src/lib/Hydra/Model/DB.pm
@@ -2,7 +2,20 @@ package Hydra::Model::DB;
 
 use strict;
 use base 'Catalyst::Model::DBIC::Schema';
-use Hydra::Helper::Nix;
+
+sub getHydraPath {
+    my $dir = $ENV{"HYDRA_DATA"} || "/var/lib/hydra";
+    die "The HYDRA_DATA directory ($dir) does not exist!\n" unless -d $dir;
+    return $dir;
+}
+
+sub getHydraDBPath {
+    my $db = $ENV{"HYDRA_DBI"};
+    return $db if defined $db;
+    my $path = getHydraPath . '/hydra.sqlite';
+    die "The Hydra database ($path) not exist!\n" unless -f $path;
+    return "dbi:SQLite:$path";
+}
 
 __PACKAGE__->config(
     schema_class => 'Hydra::Schema',
diff --git a/src/lib/Hydra/Schema/BuildInputs.pm b/src/lib/Hydra/Schema/BuildInputs.pm
index 3cf6c687..3ba61a46 100644
--- a/src/lib/Hydra/Schema/BuildInputs.pm
+++ b/src/lib/Hydra/Schema/BuildInputs.pm
@@ -156,16 +156,4 @@ __PACKAGE__->belongs_to(
 # Created by DBIx::Class::Schema::Loader v0.07014 @ 2011-12-05 14:15:43
 # DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:yaqa9gcGx9Z+Nfr3xgX28g
 
-use Hydra::Helper::Nix;
-
-sub addSequence {
-  my $hydradbi = getHydraDBPath ;
-  if ($hydradbi =~ m/^dbi:Pg/) {
-    __PACKAGE__->sequence('builds_id_seq');
-  }
-} 
-
-addSequence ;
-
-# You can replace this text with custom content, and it will be preserved on regeneration
 1;
diff --git a/src/lib/Hydra/Schema/Builds.pm b/src/lib/Hydra/Schema/Builds.pm
index 12040b92..def719e8 100644
--- a/src/lib/Hydra/Schema/Builds.pm
+++ b/src/lib/Hydra/Schema/Builds.pm
@@ -432,8 +432,6 @@ __PACKAGE__->has_many(
 # Created by DBIx::Class::Schema::Loader v0.07014 @ 2012-02-29 18:56:22
 # DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:w16c86FRReLPdA8H0yTIRg
 
-use Hydra::Helper::Nix;
-
 __PACKAGE__->has_many(
   "dependents",
   "Hydra::Schema::BuildInputs",
@@ -456,13 +454,6 @@ __PACKAGE__->has_one(
   },
 );
 
-sub addSequence {
-    my $hydradbi = getHydraDBPath;
-    if ($hydradbi =~ m/^dbi:Pg/) {
-        __PACKAGE__->sequence('builds_id_seq');
-    }
-}
-
 sub makeSource {
     my ($name, $query) = @_;
     my $source = __PACKAGE__->result_source_instance();
@@ -526,8 +517,6 @@ QUERY
     );
 }
 
-addSequence;
-
 makeQueries('', "");
 makeQueries('ForProject', "and project = ?");
 makeQueries('ForJobset', "and project = ? and jobset = ?");
diff --git a/src/lib/Hydra/Schema/JobsetEvals.pm b/src/lib/Hydra/Schema/JobsetEvals.pm
index f3feaa16..27145d15 100644
--- a/src/lib/Hydra/Schema/JobsetEvals.pm
+++ b/src/lib/Hydra/Schema/JobsetEvals.pm
@@ -145,14 +145,6 @@ __PACKAGE__->belongs_to("project", "Hydra::Schema::Projects", { name => "project
 # Created by DBIx::Class::Schema::Loader v0.07014 @ 2011-12-05 14:15:43
 # DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:eQtF5bcR/qZ625LxWBc7ug
 
-use Hydra::Helper::Nix;
-
-# !!! Ugly, should be generated.
-my $hydradbi = getHydraDBPath;
-if ($hydradbi =~ m/^dbi:Pg/) {
-    __PACKAGE__->sequence('jobsetevals_id_seq');
-}
-
 __PACKAGE__->has_many(
   "buildIds",
   "Hydra::Schema::JobsetEvalMembers",
diff --git a/src/lib/Hydra/Schema/NewsItems.pm b/src/lib/Hydra/Schema/NewsItems.pm
index 2c731440..6b4aa9d1 100644
--- a/src/lib/Hydra/Schema/NewsItems.pm
+++ b/src/lib/Hydra/Schema/NewsItems.pm
@@ -86,12 +86,4 @@ __PACKAGE__->belongs_to("author", "Hydra::Schema::Users", { username => "author"
 # Created by DBIx::Class::Schema::Loader v0.07014 @ 2011-12-05 14:15:43
 # DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:YRMh0QI4JezFLj7nywGu6Q
 
-use Hydra::Helper::Nix;
-
-# !!! Ugly, should be generated.
-my $hydradbi = getHydraDBPath;
-if ($hydradbi =~ m/^dbi:Pg/) {
-    __PACKAGE__->sequence('newsitems_id_seq');
-}
-
 1;
diff --git a/src/script/hydra-build b/src/script/hydra-build
index 60e27e64..aeb70574 100755
--- a/src/script/hydra-build
+++ b/src/script/hydra-build
@@ -6,6 +6,7 @@ use File::stat;
 use Nix::Store;
 use Hydra::Schema;
 use Hydra::Helper::Nix;
+use Hydra::Model::DB;
 use Hydra::Helper::AddBuilds;
 use Email::Sender::Simple qw(sendmail);
 use Email::Sender::Transport::SMTP;
@@ -21,7 +22,7 @@ use feature qw/switch/;
 
 STDOUT->autoflush();
 
-my $db = openHydraDB;
+my $db = Hydra::Model::DB->new();
 
 
 my %config = new Config::General(getHydraConf)->getall;
diff --git a/src/script/hydra-evaluator b/src/script/hydra-evaluator
index 2765458f..9b0165a0 100755
--- a/src/script/hydra-evaluator
+++ b/src/script/hydra-evaluator
@@ -5,8 +5,8 @@ use feature 'switch';
 use Hydra::Schema;
 use Hydra::Helper::Nix;
 use Hydra::Helper::AddBuilds;
+use Hydra::Model::DB;
 use Digest::SHA qw(sha256_hex);
-
 use Email::Sender::Simple qw(sendmail);
 use Email::Sender::Transport::SMTP;
 use Email::Simple;
@@ -17,7 +17,7 @@ use Data::Dump qw(dump);
 
 STDOUT->autoflush();
 
-my $db = openHydraDB;
+my $db = Hydra::Model::DB->new();
 my %config = new Config::General(getHydraConf)->getall;
 
 
diff --git a/src/script/hydra-init b/src/script/hydra-init
index a0cbe146..0163d30a 100755
--- a/src/script/hydra-init
+++ b/src/script/hydra-init
@@ -3,11 +3,12 @@
 use strict;
 use Hydra::Schema;
 use Hydra::Helper::Nix;
+use Hydra::Model::DB;
 use File::Slurp;
 use SQL::SplitStatement;
 use List::Util qw(max);
 
-my $db = openHydraDB;
+my $db = Hydra::Model::DB->new();
 my $dbh = $db->storage->dbh;
 $dbh->{RaiseError} = 1;
 
diff --git a/src/script/hydra-queue-runner b/src/script/hydra-queue-runner
index 745a990c..5d774d8e 100755
--- a/src/script/hydra-queue-runner
+++ b/src/script/hydra-queue-runner
@@ -6,11 +6,12 @@ use File::Basename;
 use POSIX qw(dup2 :sys_wait_h);
 use Hydra::Schema;
 use Hydra::Helper::Nix;
+use Hydra::Model::DB;
 use IO::Handle;
 use Nix::Store;
 
-chdir getHydraPath or die;
-my $db = openHydraDB;
+chdir Hydra::Model::DB::getHydraPath or die;
+my $db = Hydra::Model::DB->new();
 
 STDOUT->autoflush();
 
diff --git a/src/script/hydra-update-gc-roots b/src/script/hydra-update-gc-roots
index b86c2507..d0341897 100755
--- a/src/script/hydra-update-gc-roots
+++ b/src/script/hydra-update-gc-roots
@@ -6,9 +6,10 @@ use File::Basename;
 use Nix::Store;
 use Hydra::Schema;
 use Hydra::Helper::Nix;
+use Hydra::Model::DB;
 use POSIX qw(strftime);
 
-my $db = openHydraDB;
+my $db = Hydra::Model::DB->new();
 
 
 my %roots;
@@ -75,7 +76,7 @@ foreach my $project ($db->resultset('Projects')->search({}, { order_by => ["name
 
         # If the jobset has been disabled for more than one week, than
         # don't keep its builds anymore.
-        if ($jobset->enabled == 0 && (time() - $jobset->lastcheckedtime > (7 * 24 * 3600))) {
+        if ($jobset->enabled == 0 && (time() - ($jobset->lastcheckedtime || 0) > (7 * 24 * 3600))) {
             print STDERR "*** skipping disabled jobset ", $project->name, ":", $jobset->name, "\n";
             next;
         }