diff --git a/src/Hydra/lib/Hydra/Schema.pm b/src/Hydra/lib/Hydra/Schema.pm
index 67f4f5ba..f345f22a 100644
--- a/src/Hydra/lib/Hydra/Schema.pm
+++ b/src/Hydra/lib/Hydra/Schema.pm
@@ -8,8 +8,8 @@ use base 'DBIx::Class::Schema';
 __PACKAGE__->load_classes;
 
 
-# Created by DBIx::Class::Schema::Loader v0.04005 @ 2008-11-25 19:24:09
-# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:TBu7KS/p71rCVTI6cl7Thw
+# Created by DBIx::Class::Schema::Loader v0.04005 @ 2008-11-26 14:37:07
+# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:E0tjF/wARKGxMml3bYcLFQ
 
 
 # You can replace this text with custom content, and it will be preserved on regeneration
diff --git a/src/Hydra/lib/Hydra/Schema/Buildinputs.pm b/src/Hydra/lib/Hydra/Schema/Buildinputs.pm
index 6309293c..2fe7fa50 100644
--- a/src/Hydra/lib/Hydra/Schema/Buildinputs.pm
+++ b/src/Hydra/lib/Hydra/Schema/Buildinputs.pm
@@ -36,8 +36,8 @@ __PACKAGE__->belongs_to("build", "Hydra::Schema::Builds", { id => "build" });
 __PACKAGE__->belongs_to("dependency", "Hydra::Schema::Builds", { id => "dependency" });
 
 
-# Created by DBIx::Class::Schema::Loader v0.04005 @ 2008-11-25 19:24:09
-# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:Z/kUflLoTmq+0tM82kxVYw
+# Created by DBIx::Class::Schema::Loader v0.04005 @ 2008-11-26 14:37:07
+# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:ACPzMIxSYRMXkv8LGwR6lA
 
 
 # You can replace this text with custom content, and it will be preserved on regeneration
diff --git a/src/Hydra/lib/Hydra/Schema/Buildproducts.pm b/src/Hydra/lib/Hydra/Schema/Buildproducts.pm
index 115a698e..84149a38 100644
--- a/src/Hydra/lib/Hydra/Schema/Buildproducts.pm
+++ b/src/Hydra/lib/Hydra/Schema/Buildproducts.pm
@@ -33,8 +33,8 @@ __PACKAGE__->set_primary_key("build", "productnr");
 __PACKAGE__->belongs_to("build", "Hydra::Schema::Builds", { id => "build" });
 
 
-# Created by DBIx::Class::Schema::Loader v0.04005 @ 2008-11-25 19:24:09
-# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:gmWXPz3CSN4WOUTrcxXzQw
+# Created by DBIx::Class::Schema::Loader v0.04005 @ 2008-11-26 14:37:07
+# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:lREoFKnRpeyIMd+9AxbYuQ
 
 
 # You can replace this text with custom content, and it will be preserved on regeneration
diff --git a/src/Hydra/lib/Hydra/Schema/Buildresultinfo.pm b/src/Hydra/lib/Hydra/Schema/Buildresultinfo.pm
index bfe69346..0ee60082 100644
--- a/src/Hydra/lib/Hydra/Schema/Buildresultinfo.pm
+++ b/src/Hydra/lib/Hydra/Schema/Buildresultinfo.pm
@@ -29,8 +29,8 @@ __PACKAGE__->set_primary_key("id");
 __PACKAGE__->belongs_to("id", "Hydra::Schema::Builds", { id => "id" });
 
 
-# Created by DBIx::Class::Schema::Loader v0.04005 @ 2008-11-25 19:24:09
-# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:7iNqQ1Q912X3/TiDPk/RWA
+# Created by DBIx::Class::Schema::Loader v0.04005 @ 2008-11-26 14:37:07
+# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:6wMlFDXyRr0ElqsdFbRc3g
 
 
 # You can replace this text with custom content, and it will be preserved on regeneration
diff --git a/src/Hydra/lib/Hydra/Schema/Builds.pm b/src/Hydra/lib/Hydra/Schema/Builds.pm
index e0c40be9..dfc08545 100644
--- a/src/Hydra/lib/Hydra/Schema/Builds.pm
+++ b/src/Hydra/lib/Hydra/Schema/Builds.pm
@@ -70,8 +70,8 @@ __PACKAGE__->has_many(
 );
 
 
-# Created by DBIx::Class::Schema::Loader v0.04005 @ 2008-11-25 19:24:09
-# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:u9AGxpJIQFY0RAILvnaIKA
+# Created by DBIx::Class::Schema::Loader v0.04005 @ 2008-11-26 14:37:07
+# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:cX3mAlsEB9POMvmCcoWn6A
 
 __PACKAGE__->has_many(dependents => 'Hydra::Schema::Buildinputs', 'dependency');
 
diff --git a/src/Hydra/lib/Hydra/Schema/Buildschedulinginfo.pm b/src/Hydra/lib/Hydra/Schema/Buildschedulinginfo.pm
index a7a3571f..8f329601 100644
--- a/src/Hydra/lib/Hydra/Schema/Buildschedulinginfo.pm
+++ b/src/Hydra/lib/Hydra/Schema/Buildschedulinginfo.pm
@@ -23,8 +23,8 @@ __PACKAGE__->set_primary_key("id");
 __PACKAGE__->belongs_to("id", "Hydra::Schema::Builds", { id => "id" });
 
 
-# Created by DBIx::Class::Schema::Loader v0.04005 @ 2008-11-25 19:24:09
-# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:cqaeltO0pjpVPv2Ah54SQg
+# Created by DBIx::Class::Schema::Loader v0.04005 @ 2008-11-26 14:37:07
+# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:O6bwijQ4R6Ke9QjYjsuUsA
 
 
 # You can replace this text with custom content, and it will be preserved on regeneration
diff --git a/src/Hydra/lib/Hydra/Schema/Buildsteps.pm b/src/Hydra/lib/Hydra/Schema/Buildsteps.pm
index 054db79d..bd6e430b 100644
--- a/src/Hydra/lib/Hydra/Schema/Buildsteps.pm
+++ b/src/Hydra/lib/Hydra/Schema/Buildsteps.pm
@@ -35,8 +35,8 @@ __PACKAGE__->set_primary_key("id", "stepnr");
 __PACKAGE__->belongs_to("id", "Hydra::Schema::Builds", { id => "id" });
 
 
-# Created by DBIx::Class::Schema::Loader v0.04005 @ 2008-11-25 19:24:09
-# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:dJac1j1n7A2sQBrfgdLdYg
+# Created by DBIx::Class::Schema::Loader v0.04005 @ 2008-11-26 14:37:07
+# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:7vdFywkKYZeLSow8AijaUA
 
 
 # You can replace this text with custom content, and it will be preserved on regeneration
diff --git a/src/Hydra/lib/Hydra/Schema/Cachedpathinputs.pm b/src/Hydra/lib/Hydra/Schema/Cachedpathinputs.pm
index cf14989e..5b848c0c 100644
--- a/src/Hydra/lib/Hydra/Schema/Cachedpathinputs.pm
+++ b/src/Hydra/lib/Hydra/Schema/Cachedpathinputs.pm
@@ -22,8 +22,8 @@ __PACKAGE__->add_columns(
 __PACKAGE__->set_primary_key("srcpath", "sha256hash");
 
 
-# Created by DBIx::Class::Schema::Loader v0.04005 @ 2008-11-25 19:24:09
-# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:5sHH9qbQ5WtUf2oRjXbwuw
+# Created by DBIx::Class::Schema::Loader v0.04005 @ 2008-11-26 14:37:07
+# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:dPQ2YTZIUdMRwBbiu1qwUw
 
 
 # You can replace this text with custom content, and it will be preserved on regeneration
diff --git a/src/Hydra/lib/Hydra/Schema/Cachedsubversioninputs.pm b/src/Hydra/lib/Hydra/Schema/Cachedsubversioninputs.pm
index bc15f163..3bda4b38 100644
--- a/src/Hydra/lib/Hydra/Schema/Cachedsubversioninputs.pm
+++ b/src/Hydra/lib/Hydra/Schema/Cachedsubversioninputs.pm
@@ -20,8 +20,8 @@ __PACKAGE__->add_columns(
 __PACKAGE__->set_primary_key("uri", "revision");
 
 
-# Created by DBIx::Class::Schema::Loader v0.04005 @ 2008-11-25 19:24:09
-# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:k1xO/rt0fxTjvtkPY/Jwfw
+# Created by DBIx::Class::Schema::Loader v0.04005 @ 2008-11-26 14:37:07
+# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:EVNo1URK0XJTQo+KXHlmpA
 
 
 # You can replace this text with custom content, and it will be preserved on regeneration
diff --git a/src/Hydra/lib/Hydra/Schema/Jobsetinputalts.pm b/src/Hydra/lib/Hydra/Schema/Jobsetinputalts.pm
index 8f32fdd4..595428a9 100644
--- a/src/Hydra/lib/Hydra/Schema/Jobsetinputalts.pm
+++ b/src/Hydra/lib/Hydra/Schema/Jobsetinputalts.pm
@@ -22,6 +22,8 @@ __PACKAGE__->add_columns(
   { data_type => "integer", is_nullable => 0, size => undef },
   "tag",
   { data_type => "text", is_nullable => 0, size => undef },
+  "boolean",
+  { data_type => "integer", is_nullable => 0, size => undef },
 );
 __PACKAGE__->set_primary_key("project", "jobset", "input", "altnr");
 __PACKAGE__->belongs_to(
@@ -31,8 +33,8 @@ __PACKAGE__->belongs_to(
 );
 
 
-# Created by DBIx::Class::Schema::Loader v0.04005 @ 2008-11-25 19:24:09
-# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:B8hAt4GezVJ1/uo4ZQ3Q2g
+# Created by DBIx::Class::Schema::Loader v0.04005 @ 2008-11-26 14:37:07
+# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:eM2dwDI3lL5EHwUA5m2pDg
 
 
 # You can replace this text with custom content, and it will be preserved on regeneration
diff --git a/src/Hydra/lib/Hydra/Schema/Jobsetinputs.pm b/src/Hydra/lib/Hydra/Schema/Jobsetinputs.pm
index 2ae7dd6b..887d7eba 100644
--- a/src/Hydra/lib/Hydra/Schema/Jobsetinputs.pm
+++ b/src/Hydra/lib/Hydra/Schema/Jobsetinputs.pm
@@ -43,8 +43,8 @@ __PACKAGE__->has_many(
 );
 
 
-# Created by DBIx::Class::Schema::Loader v0.04005 @ 2008-11-25 19:24:09
-# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:4ev1n8miWroPWPRoQBc0cA
+# Created by DBIx::Class::Schema::Loader v0.04005 @ 2008-11-26 14:37:07
+# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:poDHcgoqxtQf8HN7AbpnOA
 
 
 # You can replace this text with custom content, and it will be preserved on regeneration
diff --git a/src/Hydra/lib/Hydra/Schema/Jobsets.pm b/src/Hydra/lib/Hydra/Schema/Jobsets.pm
index d932cf0e..a398a35a 100644
--- a/src/Hydra/lib/Hydra/Schema/Jobsets.pm
+++ b/src/Hydra/lib/Hydra/Schema/Jobsets.pm
@@ -22,6 +22,8 @@ __PACKAGE__->add_columns(
   { data_type => "text", is_nullable => 0, size => undef },
   "errortime",
   { data_type => "integer", is_nullable => 0, size => undef },
+  "lastcheckedtime",
+  { data_type => "integer", is_nullable => 0, size => undef },
 );
 __PACKAGE__->set_primary_key("project", "name");
 __PACKAGE__->has_many(
@@ -48,8 +50,8 @@ __PACKAGE__->has_many(
 );
 
 
-# Created by DBIx::Class::Schema::Loader v0.04005 @ 2008-11-25 19:24:09
-# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:7kRl30K427lecYirFGBxew
+# Created by DBIx::Class::Schema::Loader v0.04005 @ 2008-11-26 14:37:07
+# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:BJwh19m9KHKZUMAiQ6fPAw
 
 
 # You can replace this text with custom content, and it will be preserved on regeneration
diff --git a/src/Hydra/lib/Hydra/Schema/Projects.pm b/src/Hydra/lib/Hydra/Schema/Projects.pm
index 7f6ed3c3..9ef871e7 100644
--- a/src/Hydra/lib/Hydra/Schema/Projects.pm
+++ b/src/Hydra/lib/Hydra/Schema/Projects.pm
@@ -30,8 +30,8 @@ __PACKAGE__->has_many(
 );
 
 
-# Created by DBIx::Class::Schema::Loader v0.04005 @ 2008-11-25 19:24:09
-# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:ZBkLod0Yw87pgQGAEuk7Zg
+# Created by DBIx::Class::Schema::Loader v0.04005 @ 2008-11-26 14:37:07
+# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:v/jpJlVZg1k8PDLJyZhpSA
 
 
 # You can replace this text with custom content, and it will be preserved on regeneration
diff --git a/src/Hydra/programs/Scheduler.pl b/src/Hydra/programs/Scheduler.pl
index b2b267a0..7901c4bf 100644
--- a/src/Hydra/programs/Scheduler.pl
+++ b/src/Hydra/programs/Scheduler.pl
@@ -338,6 +338,11 @@ sub checkJobAlternatives {
 sub checkJobSet {
     my ($project, $jobset) = @_;
     my $inputInfo = {};
+    
+    $db->txn_do(sub {
+        $jobset->lastcheckedtime(time);
+        $jobset->update;
+    });
 
     # Fetch the input containing the Nix expression.
     (my $exprInput) = $jobset->jobsetinputs->search({name => $jobset->nixexprinput});
diff --git a/src/Hydra/root/project.tt b/src/Hydra/root/project.tt
index 7716232b..cb97a04d 100644
--- a/src/Hydra/root/project.tt
+++ b/src/Hydra/root/project.tt
@@ -92,6 +92,14 @@
         <tt>[% INCLUDE maybeEditString param="jobset-$baseName-nixexprinput" value=jobset.nixexprinput extraClass="shortString" %]</tt>
       </td>
     </tr>
+    [% IF !edit %]
+      <tr>
+        <th>Last checked:</th>
+        <td>
+          [% PROCESS renderDateTime timestamp = jobset.lastcheckedtime %]
+        </td>
+      </tr>
+    [% END %]
     [% IF !edit && jobset.errormsg %]
       <tr>
         <th>Last evaluation error:</th>
diff --git a/src/hydra.sql b/src/hydra.sql
index cd52eb9c..c68bbae9 100644
--- a/src/hydra.sql
+++ b/src/hydra.sql
@@ -37,6 +37,8 @@ create table BuildSchedulingInfo (
     locker        text not null default '', -- !!! hostname/pid of the process building this job?
 
     logfile       text, -- if busy, the path of the logfile
+
+    disabled      integer not null default 0, -- true means hold this job until its re-enabled
     
     foreign key   (id) references Builds(id) on delete cascade -- ignored by sqlite
 );
@@ -63,6 +65,8 @@ create table BuildResultInfo (
     logfile       text, -- the path of the logfile
 
     releaseName   text, -- e.g. "patchelf-0.5pre1234"
+
+    keep          integer not null default 0, -- true means never garbage-collect the build output
     
     foreign key   (id) references Builds(id) on delete cascade -- ignored by sqlite
 );
@@ -81,11 +85,11 @@ create table BuildSteps (
 
     busy          integer not null,
 
-    status        integer,
+    status        integer, -- 0 = success, 1 = failed
 
     errorMsg      text,
 
-    startTime     integer, -- in Unix time, 0 = used cached build result
+    startTime     integer,
     stopTime      integer,
 
     primary key   (id, stepnr),
@@ -174,6 +178,7 @@ create table Jobsets (
     nixExprPath   text not null, -- relative path of the Nix expression
     errorMsg      text, -- used to signal the last evaluation error etc. for this jobset
     errorTime     integer, -- timestamp associated with errorMsg
+    lastCheckedTime integer, -- last time the scheduler looked at this jobset
     primary key   (project, name),
     foreign key   (project) references Projects(name) on delete cascade, -- ignored by sqlite
     foreign key   (project, name, nixExprInput) references JobsetInputs(project, job, name)