diff --git a/src/lib/Hydra/Schema/Builds.pm b/src/lib/Hydra/Schema/Builds.pm
index 013fd09d..53454867 100644
--- a/src/lib/Hydra/Schema/Builds.pm
+++ b/src/lib/Hydra/Schema/Builds.pm
@@ -64,6 +64,12 @@ __PACKAGE__->table("builds");
   is_foreign_key: 1
   is_nullable: 0
 
+=head2 jobset_id
+
+  data_type: 'integer'
+  is_foreign_key: 1
+  is_nullable: 1
+
 =head2 job
 
   data_type: 'text'
@@ -215,6 +221,8 @@ __PACKAGE__->add_columns(
   { data_type => "text", is_foreign_key => 1, is_nullable => 0 },
   "jobset",
   { data_type => "text", is_foreign_key => 1, is_nullable => 0 },
+  "jobset_id",
+  { data_type => "integer", is_foreign_key => 1, is_nullable => 1 },
   "job",
   { data_type => "text", is_foreign_key => 1, is_nullable => 0 },
   "nixname",
@@ -457,6 +465,26 @@ Related object: L<Hydra::Schema::Jobsets>
 __PACKAGE__->belongs_to(
   "jobset",
   "Hydra::Schema::Jobsets",
+  { id => "jobset_id" },
+  {
+    is_deferrable => 0,
+    join_type     => "LEFT",
+    on_delete     => "CASCADE",
+    on_update     => "NO ACTION",
+  },
+);
+
+=head2 jobset_project_jobset
+
+Type: belongs_to
+
+Related object: L<Hydra::Schema::Jobsets>
+
+=cut
+
+__PACKAGE__->belongs_to(
+  "jobset_project_jobset",
+  "Hydra::Schema::Jobsets",
   { name => "jobset", project => "project" },
   { is_deferrable => 0, on_delete => "NO ACTION", on_update => "CASCADE" },
 );
@@ -550,8 +578,8 @@ __PACKAGE__->many_to_many(
 );
 
 
-# Created by DBIx::Class::Schema::Loader v0.07049 @ 2020-02-06 12:22:36
-# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:H3hs+zEywsUmwTWKfSE8wQ
+# Created by DBIx::Class::Schema::Loader v0.07049 @ 2020-02-06 12:32:28
+# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:RvrINOAowDcde8Nd9VD6rQ
 
 __PACKAGE__->has_many(
   "dependents",
diff --git a/src/lib/Hydra/Schema/Jobs.pm b/src/lib/Hydra/Schema/Jobs.pm
index bdecef3a..d4126e32 100644
--- a/src/lib/Hydra/Schema/Jobs.pm
+++ b/src/lib/Hydra/Schema/Jobs.pm
@@ -47,6 +47,12 @@ __PACKAGE__->table("jobs");
   is_foreign_key: 1
   is_nullable: 0
 
+=head2 jobset_id
+
+  data_type: 'integer'
+  is_foreign_key: 1
+  is_nullable: 1
+
 =head2 name
 
   data_type: 'text'
@@ -59,6 +65,8 @@ __PACKAGE__->add_columns(
   { data_type => "text", is_foreign_key => 1, is_nullable => 0 },
   "jobset",
   { data_type => "text", is_foreign_key => 1, is_nullable => 0 },
+  "jobset_id",
+  { data_type => "integer", is_foreign_key => 1, is_nullable => 1 },
   "name",
   { data_type => "text", is_nullable => 0 },
 );
@@ -130,6 +138,26 @@ Related object: L<Hydra::Schema::Jobsets>
 __PACKAGE__->belongs_to(
   "jobset",
   "Hydra::Schema::Jobsets",
+  { id => "jobset_id" },
+  {
+    is_deferrable => 0,
+    join_type     => "LEFT",
+    on_delete     => "CASCADE",
+    on_update     => "NO ACTION",
+  },
+);
+
+=head2 jobset_project_jobset
+
+Type: belongs_to
+
+Related object: L<Hydra::Schema::Jobsets>
+
+=cut
+
+__PACKAGE__->belongs_to(
+  "jobset_project_jobset",
+  "Hydra::Schema::Jobsets",
   { name => "jobset", project => "project" },
   { is_deferrable => 0, on_delete => "CASCADE", on_update => "CASCADE" },
 );
@@ -169,7 +197,7 @@ __PACKAGE__->has_many(
 );
 
 
-# Created by DBIx::Class::Schema::Loader v0.07049 @ 2020-02-06 12:22:36
-# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:sYa6dZNK+stMAnTH0Tmn8A
+# Created by DBIx::Class::Schema::Loader v0.07049 @ 2020-02-06 12:30:58
+# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:dFusVjxb423gIEoadAw9sw
 
 1;
diff --git a/src/lib/Hydra/Schema/Jobsets.pm b/src/lib/Hydra/Schema/Jobsets.pm
index 9e9d4773..fbbb253c 100644
--- a/src/lib/Hydra/Schema/Jobsets.pm
+++ b/src/lib/Hydra/Schema/Jobsets.pm
@@ -40,6 +40,13 @@ __PACKAGE__->table("jobsets");
   data_type: 'text'
   is_nullable: 0
 
+=head2 id
+
+  data_type: 'integer'
+  is_auto_increment: 1
+  is_nullable: 0
+  sequence: 'jobsets_id_seq'
+
 =head2 project
 
   data_type: 'text'
@@ -153,6 +160,13 @@ __PACKAGE__->table("jobsets");
 __PACKAGE__->add_columns(
   "name",
   { data_type => "text", is_nullable => 0 },
+  "id",
+  {
+    data_type         => "integer",
+    is_auto_increment => 1,
+    is_nullable       => 0,
+    sequence          => "jobsets_id_seq",
+  },
   "project",
   { data_type => "text", is_foreign_key => 1, is_nullable => 0 },
   "description",
@@ -209,6 +223,20 @@ __PACKAGE__->add_columns(
 
 __PACKAGE__->set_primary_key("project", "name");
 
+=head1 UNIQUE CONSTRAINTS
+
+=head2 C<jobsets_id_unique>
+
+=over 4
+
+=item * L</id>
+
+=back
+
+=cut
+
+__PACKAGE__->add_unique_constraint("jobsets_id_unique", ["id"]);
+
 =head1 RELATIONS
 
 =head2 buildmetrics
@@ -229,7 +257,7 @@ __PACKAGE__->has_many(
   undef,
 );
 
-=head2 builds
+=head2 builds_jobset_ids
 
 Type: has_many
 
@@ -238,7 +266,22 @@ Related object: L<Hydra::Schema::Builds>
 =cut
 
 __PACKAGE__->has_many(
-  "builds",
+  "builds_jobset_ids",
+  "Hydra::Schema::Builds",
+  { "foreign.jobset_id" => "self.id" },
+  undef,
+);
+
+=head2 builds_project_jobsets
+
+Type: has_many
+
+Related object: L<Hydra::Schema::Builds>
+
+=cut
+
+__PACKAGE__->has_many(
+  "builds_project_jobsets",
   "Hydra::Schema::Builds",
   {
     "foreign.jobset"  => "self.name",
@@ -247,7 +290,7 @@ __PACKAGE__->has_many(
   undef,
 );
 
-=head2 jobs
+=head2 jobs_jobset_ids
 
 Type: has_many
 
@@ -256,7 +299,22 @@ Related object: L<Hydra::Schema::Jobs>
 =cut
 
 __PACKAGE__->has_many(
-  "jobs",
+  "jobs_jobset_ids",
+  "Hydra::Schema::Jobs",
+  { "foreign.jobset_id" => "self.id" },
+  undef,
+);
+
+=head2 jobs_project_jobsets
+
+Type: has_many
+
+Related object: L<Hydra::Schema::Jobs>
+
+=cut
+
+__PACKAGE__->has_many(
+  "jobs_project_jobsets",
   "Hydra::Schema::Jobs",
   {
     "foreign.jobset"  => "self.name",
@@ -350,8 +408,49 @@ __PACKAGE__->has_many(
 );
 
 
-# Created by DBIx::Class::Schema::Loader v0.07049 @ 2020-02-09 15:21:11
-# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:FVP1/AWjdKTlY6djrG592A
+# Created by DBIx::Class::Schema::Loader v0.07049 @ 2020-02-09 15:32:17
+# DO NOT MODIFY THIS OR ANYTHING ABOVE! md5sum:P8+t7rgpOqkGwRdM2b+3Bw
+
+
+=head2 builds
+
+Type: has_many
+
+Related object: L<Hydra::Schema::Builds>
+
+=cut
+
+__PACKAGE__->has_many(
+  "builds",
+  "Hydra::Schema::Builds",
+  {
+    "foreign.jobset"  => "self.name",
+    "foreign.project" => "self.project",
+  },
+  undef,
+);
+
+=head2 jobs
+
+Type: has_many
+
+Related object: L<Hydra::Schema::Jobs>
+
+=cut
+
+__PACKAGE__->has_many(
+  "jobs",
+  "Hydra::Schema::Jobs",
+  {
+    "foreign.jobset"  => "self.name",
+    "foreign.project" => "self.project",
+  },
+  undef,
+);
+
+__PACKAGE__->add_column(
+    "+id" => { retrieve_on_insert => 1 }
+);
 
 my %hint = (
     columns => [
diff --git a/src/script/Makefile.am b/src/script/Makefile.am
index 5852bc85..9deb6f29 100644
--- a/src/script/Makefile.am
+++ b/src/script/Makefile.am
@@ -3,6 +3,7 @@ EXTRA_DIST =					\
   hydra-eval-guile-jobs.in
 
 distributable_scripts =				\
+  hydra-backfill-ids				\
   hydra-init					\
   hydra-eval-jobset				\
   hydra-server					\
diff --git a/src/script/hydra-backfill-ids b/src/script/hydra-backfill-ids
new file mode 100755
index 00000000..d9fc362a
--- /dev/null
+++ b/src/script/hydra-backfill-ids
@@ -0,0 +1,164 @@
+#! /usr/bin/env perl
+
+use strict;
+use utf8;
+use Hydra::Model::DB;
+
+STDOUT->autoflush();
+STDERR->autoflush(1);
+binmode STDERR, ":encoding(utf8)";
+
+my $db = Hydra::Model::DB->new();
+my $vacuum = $db->storage->dbh->prepare("VACUUM;");
+
+my $dryRun = defined $ENV{'HYDRA_DRY_RUN'};
+
+my $batchSize = 10000;
+my $iterationsPerVacuum = 500;
+
+sub backfillJobsJobsetId {
+    my ($skipLocked) = @_;
+    my $logPrefix;
+
+    if ($skipLocked) {
+        $logPrefix = "(pass 1/2)";
+    } else {
+        $logPrefix = "(pass 2/2)";
+    }
+
+    print STDERR "$logPrefix Backfilling Jobs records where jobset_id is NULL...\n";
+
+    my $totalToGoSth = $db->storage->dbh->prepare(<<QUERY);
+SELECT COUNT(*) FROM jobs WHERE jobset_id IS NULL
+QUERY
+
+    $totalToGoSth->execute();
+    my ($totalToGo) = $totalToGoSth->fetchrow_array;
+
+    my $skipLockedStmt = $skipLocked ? "FOR UPDATE SKIP LOCKED" : "";
+    my $update10kJobs = $db->storage->dbh->prepare(<<QUERY);
+UPDATE jobs
+SET jobset_id = (
+  SELECT jobsets.id
+  FROM jobsets
+  WHERE jobsets.name = jobs.jobset
+    AND jobsets.project = jobs.project
+)
+WHERE (jobs.project, jobs.jobset, jobs.name) in (
+  SELECT jobsprime.project, jobsprime.jobset, jobsprime.name
+  FROM jobs jobsprime
+  WHERE jobsprime.jobset_id IS NULL
+  $skipLockedStmt
+  LIMIT ?
+);
+QUERY
+
+    print STDERR "$logPrefix Total Jobs records without a jobset_id: $totalToGo\n";
+
+    my $iteration = 0;
+    my $affected;
+    do {
+        $iteration++;
+        $affected = $update10kJobs->execute($batchSize);
+        print STDERR "$logPrefix (batch #$iteration; $totalToGo remaining) Jobs.jobset_id: affected $affected rows...\n";
+        $totalToGo -= $affected;
+
+        if ($iteration % $iterationsPerVacuum == 0) {
+            print STDERR "$logPrefix (batch #$iteration) Vacuuming...\n";
+            $vacuum->execute();
+        }
+    } while ($affected > 0);
+
+
+    if ($skipLocked) {
+        backfillJobsJobsetId(0);
+    }
+}
+
+
+sub backfillBuildsJobsetId {
+    my ($skipLocked) = @_;
+    my $logPrefix;
+
+    if ($skipLocked) {
+        $logPrefix = "(pass 1/2)";
+        print STDERR "$logPrefix Backfilling unlocked Builds records where jobset_id is NULL...\n";
+    } else {
+        $logPrefix = "(pass 2/2)";
+        print STDERR "$logPrefix Backfilling all Builds records where jobset_id is NULL...\n";
+    }
+
+    my $skipLockedStmt = $skipLocked ? "FOR UPDATE SKIP LOCKED" : "";
+    my $update10kBuilds = $db->storage->dbh->prepare(<<"QUERY");
+WITH updateprogress AS (
+  UPDATE builds
+  SET jobset_id = (
+    SELECT jobsets.id
+    FROM jobsets
+    WHERE jobsets.name = builds.jobset
+      AND jobsets.project = builds.project
+  )
+  WHERE builds.id in (
+    SELECT buildprime.id
+    FROM builds buildprime
+    WHERE buildprime.jobset_id IS NULL
+      AND buildprime.id >= ?
+    ORDER BY buildprime.id
+    $skipLockedStmt
+    LIMIT ?
+  )
+  RETURNING id
+)
+SELECT
+  count(*) AS affected,
+  max(updateprogress.id) AS highest_id
+FROM updateprogress;
+
+QUERY
+
+    my $lowestNullIdSth = $db->storage->dbh->prepare(<<QUERY);
+ SELECT id FROM builds WHERE jobset_id IS NULL ORDER BY id LIMIT 1
+QUERY
+    $lowestNullIdSth->execute();
+    my ($highestId) = $lowestNullIdSth->fetchrow_array;
+
+    my $totalToGoSth = $db->storage->dbh->prepare(<<QUERY);
+SELECT COUNT(*) FROM builds WHERE jobset_id IS NULL AND id >= ?
+QUERY
+    $totalToGoSth->execute($highestId);
+    my ($totalToGo) = $totalToGoSth->fetchrow_array;
+
+    print STDERR "$logPrefix Total Builds records without a jobset_id: $totalToGo, starting at $highestId\n";
+
+    my $iteration = 0;
+    my $affected;
+    do {
+        my $previousHighId = $highestId;
+        $iteration++;
+        $update10kBuilds->execute($highestId, $batchSize);
+        ($affected, $highestId) = $update10kBuilds->fetchrow_array;
+
+        print STDERR "$logPrefix (batch #$iteration; $totalToGo remaining) Builds.jobset_id: affected $affected rows; max ID: $previousHighId -> $highestId\n";
+        $totalToGo -= $affected;
+
+        if ($iteration % $iterationsPerVacuum == 0) {
+            print STDERR "$logPrefix (batch #$iteration) Vacuuming...\n";
+            $vacuum->execute();
+        }
+    } while ($affected > 0);
+
+    if ($skipLocked) {
+        backfillBuildsJobsetId(0);
+    }
+}
+
+die "syntax: $0\n" unless @ARGV == 0;
+
+print STDERR "Beginning with a VACUUM\n";
+$vacuum->execute();
+
+backfillJobsJobsetId(1);
+backfillBuildsJobsetId(1);
+
+print STDERR "Ending with a VACUUM\n";
+$vacuum->execute();
diff --git a/src/script/hydra-eval-jobset b/src/script/hydra-eval-jobset
index fcc60a6c..d0cc3e8a 100755
--- a/src/script/hydra-eval-jobset
+++ b/src/script/hydra-eval-jobset
@@ -417,7 +417,12 @@ sub checkBuild {
     my $build;
 
     txn_do($db, sub {
-        my $job = $jobset->jobs->update_or_create({ name => $jobName });
+        my $job = $jobset->jobs->update_or_create({
+            name => $jobName,
+            jobset_id => $jobset->id,
+            project => $jobset->project,
+            jobset => $jobset->name,
+        });
 
         # Don't add a build that has already been scheduled for this
         # job, or has been built but is still a "current" build for
@@ -464,6 +469,9 @@ sub checkBuild {
         # Add the build to the database.
         $build = $job->builds->create(
             { timestamp => $time
+            , project => $jobset->project
+            , jobset => $jobset->name
+            , jobset_id => $jobset->id
             , description => null($buildInfo->{description})
             , license => null($buildInfo->{license})
             , homepage => null($buildInfo->{homepage})
diff --git a/src/script/hydra-init b/src/script/hydra-init
index d813d9fe..1a5f2439 100755
--- a/src/script/hydra-init
+++ b/src/script/hydra-init
@@ -44,6 +44,17 @@ my @versions = $db->resultset('SchemaVersion')->all;
 die "couldn't get Hydra schema version!" if scalar @versions != 1;
 my $schemaVersion = $versions[0]->version;
 
+if ($schemaVersion <= 60) {
+    print STDERR <<QUOTE;
+WARNING: Schema version 62 and 63 make nullable jobset_id fields on
+         Builds and Jobs non-nullable. On big Hydra servers, this
+         migration will take many hours. Because of that, the
+         migration is not automatic, and must be performed manually.
+
+         To backfill these IDs, run: hydra-fill-ids
+QUOTE
+}
+
 for (my $n = $schemaVersion; $n < $maxSchemaVersion; $n++) {
     my $m = $n + 1;
     print STDERR "upgrading Hydra schema from version $n to $m\n";
diff --git a/src/sql/hydra.sql b/src/sql/hydra.sql
index 33ecab4d..8349e3be 100644
--- a/src/sql/hydra.sql
+++ b/src/sql/hydra.sql
@@ -52,6 +52,7 @@ create table ProjectMembers (
 -- describing build jobs.
 create table Jobsets (
     name          text not null,
+    id            serial not null,
     project       text not null,
     description   text,
     nixExprInput  text, -- name of the jobsetInput containing the Nix or Guix expression
@@ -76,7 +77,8 @@ create table Jobsets (
     check ((type = 0) = (nixExprInput is not null and nixExprPath is not null)),
     check ((type = 1) = (flake is not null)),
     primary key   (project, name),
-    foreign key   (project) references Projects(name) on delete cascade on update cascade
+    foreign key   (project) references Projects(name) on delete cascade on update cascade,
+    constraint    Jobsets_id_unique UNIQUE(id)
 #ifdef SQLITE
     ,
     foreign key   (project, name, nixExprInput) references JobsetInputs(project, jobset, name)
@@ -144,9 +146,11 @@ create table JobsetInputAlts (
 create table Jobs (
     project       text not null,
     jobset        text not null,
+    jobset_id     integer null,
     name          text not null,
 
     primary key   (project, jobset, name),
+    foreign key   (jobset_id) references Jobsets(id) on delete cascade,
     foreign key   (project) references Projects(name) on delete cascade on update cascade,
     foreign key   (project, jobset) references Jobsets(project, name) on delete cascade on update cascade
 );
@@ -166,6 +170,7 @@ create table Builds (
     -- Info about the inputs.
     project       text not null,
     jobset        text not null,
+    jobset_id     integer null,
     job           text not null,
 
     -- Info about the build result.
@@ -232,6 +237,7 @@ create table Builds (
     check (finished = 0 or (stoptime is not null and stoptime != 0)),
     check (finished = 0 or (starttime is not null and starttime != 0)),
 
+    foreign key (jobset_id) references Jobsets(id) on delete cascade,
     foreign key (project) references Projects(name) on update cascade,
     foreign key (project, jobset) references Jobsets(project, name) on update cascade,
     foreign key (project, jobset, job) references Jobs(project, jobset, name) on update cascade
diff --git a/src/sql/upgrade-59.sql b/src/sql/upgrade-59.sql
new file mode 100644
index 00000000..d0a28971
--- /dev/null
+++ b/src/sql/upgrade-59.sql
@@ -0,0 +1,4 @@
+-- will automatically add unique IDs to Jobsets.
+ALTER TABLE Jobsets
+  ADD COLUMN id SERIAL NOT NULL,
+  ADD CONSTRAINT Jobsets_id_unique UNIQUE (id);
diff --git a/src/sql/upgrade-60.sql b/src/sql/upgrade-60.sql
new file mode 100644
index 00000000..3cdb00c3
--- /dev/null
+++ b/src/sql/upgrade-60.sql
@@ -0,0 +1,10 @@
+-- Add the jobset_id columns to the Jobs table. This will go
+-- quickly, since the field is nullable. Note this is just part one of
+-- this migration. Future steps involve a piecemeal backfilling, and
+-- then making the column non-null.
+
+ALTER TABLE Jobs
+  ADD COLUMN jobset_id integer NULL,
+  ADD FOREIGN KEY (jobset_id)
+      REFERENCES Jobsets(id)
+      ON DELETE CASCADE;
diff --git a/src/sql/upgrade-61.sql b/src/sql/upgrade-61.sql
new file mode 100644
index 00000000..bfa6b8b3
--- /dev/null
+++ b/src/sql/upgrade-61.sql
@@ -0,0 +1,10 @@
+-- Add the jobset_id columns to the Builds table. This will go
+-- quickly, since the field is nullable. Note this is just part one of
+-- this migration. Future steps involve a piecemeal backfilling, and
+-- then making the column non-null.
+
+ALTER TABLE Builds
+  ADD COLUMN jobset_id integer NULL,
+  ADD FOREIGN KEY (jobset_id)
+      REFERENCES Jobsets(id)
+      ON DELETE CASCADE;