diff --git a/guix-data-service/jobs/load-new-guix-revision.scm b/guix-data-service/jobs/load-new-guix-revision.scm
index 7eb4425..7c9a772 100644
--- a/guix-data-service/jobs/load-new-guix-revision.scm
+++ b/guix-data-service/jobs/load-new-guix-revision.scm
@@ -1595,7 +1595,13 @@ WHERE job_id = $1")
                                package-derivation-ids)
               (simple-format
                #t "Successfully loaded ~A package/derivation pairs\n"
-               ids-count))))
+               ids-count))
+
+            (with-time-logging
+                "insert-guix-revision-package-derivation-distribution-counts"
+              (insert-guix-revision-package-derivation-distribution-counts
+               conn
+               guix-revision-id))))
         #t)
       (lambda (key . args)
         (simple-format (current-error-port)
diff --git a/guix-data-service/model/guix-revision-package-derivation.scm b/guix-data-service/model/guix-revision-package-derivation.scm
index 5095b42..cb73114 100644
--- a/guix-data-service/model/guix-revision-package-derivation.scm
+++ b/guix-data-service/model/guix-revision-package-derivation.scm
@@ -16,8 +16,16 @@
 ;;; <http://www.gnu.org/licenses/>.
 
 (define-module (guix-data-service model guix-revision-package-derivation)
+  #:use-module (ice-9 match)
+  #:use-module (ice-9 threads)
   #:use-module (squee)
-  #:export (insert-guix-revision-package-derivations))
+  #:use-module (guix-data-service database)
+  #:export (insert-guix-revision-package-derivations
+
+            insert-guix-revision-package-derivation-distribution-counts
+            backfill-guix-revision-package-derivation-distribution-counts
+
+            get-sql-to-select-package-and-related-derivations-for-revision))
 
 (define (insert-guix-revision-package-derivations
          conn guix-revision-id package-derivation-ids)
@@ -35,3 +43,250 @@
                    ";"))
 
   (exec-query conn insert))
+
+(define (insert-guix-revision-package-derivation-distribution-counts
+         conn
+         guix-revision-id)
+  (define system-ids-and-targets
+    (exec-query
+     conn
+     "
+SELECT DISTINCT system_id, target
+FROM package_derivations
+INNER JOIN guix_revision_package_derivations
+  ON package_derivations.id = guix_revision_package_derivations.package_derivation_id
+WHERE revision_id = $1"
+     (list guix-revision-id)))
+
+  (define (get-count-for-next-level system target level-counts)
+    (define next-level
+      (length level-counts))
+
+    (define query
+      (string-append
+       (simple-format
+        #f
+        "
+WITH l0 AS (
+  SELECT derivation_id
+  FROM package_derivations
+  INNER JOIN guix_revision_package_derivations
+    ON package_derivations.id
+        = guix_revision_package_derivations.package_derivation_id
+  WHERE revision_id = 19411
+    AND system_id = 4
+    AND target = $STR$$STR$~A
+)"
+        (if (= next-level 0)
+            ""
+            (simple-format
+             #f
+             "
+  LIMIT ~A"
+             (car level-counts))))
+       (if (= next-level 0)
+           ""
+           (string-join
+            (map
+             (match-lambda*
+               ((level count)
+                (simple-format
+                 #f
+                 ", l~A AS (
+  (
+    SELECT derivation_outputs.derivation_id
+    FROM derivation_outputs WHERE derivation_outputs.id IN (
+      SELECT DISTINCT derivation_inputs.derivation_output_id
+      FROM l~A
+      INNER JOIN derivation_inputs
+        ON l~A.derivation_id = derivation_inputs.derivation_id
+    )
+  ) EXCEPT (~A
+  )~A
+)"
+                 level
+                 (- level 1)
+                 (- level 1)
+                 (string-join
+                  (map
+                   (lambda (level)
+                     (simple-format
+                      #f
+                      "      SELECT derivation_id FROM l~A"
+                      level))
+                   (iota level))
+                  "
+    UNION ALL")
+                 (if count
+                     (simple-format
+                      #f
+                      "
+  LIMIT ~A"
+                      count)
+                     ""))))
+             (iota (length level-counts) 1)
+             (append (cdr level-counts) '(#f)))
+            ""))
+       (simple-format
+        #f
+        "
+SELECT COUNT(*) FROM l~A"
+        (length level-counts))))
+
+    (string->number
+     (caar
+      (exec-query
+       conn
+       query))))
+
+  (define (insert-level-count system-id target level count)
+    (exec-query
+     conn
+     "
+INSERT INTO guix_revision_package_derivation_distribution_counts
+VALUES ($1, $2, $3, $4, $5)"
+     (list guix-revision-id
+           system-id
+           target
+           (number->string level)
+           (number->string count))))
+
+  (for-each
+   (match-lambda
+     ((system-id target)
+
+      (let loop ((level-counts '()))
+        (let ((level (length level-counts))
+              (count (get-count-for-next-level system-id target level-counts)))
+          (unless (= count 0)
+            (insert-level-count system-id target level count)
+            (loop (append level-counts (list count))))))))
+   system-ids-and-targets))
+
+(define (backfill-guix-revision-package-derivation-distribution-counts)
+  (define revision-ids
+    (with-thread-postgresql-connection
+     (lambda (conn)
+       (map
+        car
+        (exec-query
+         conn
+         "
+  SELECT id
+  FROM guix_revisions
+EXCEPT
+  SELECT guix_revision_id
+  FROM guix_revision_package_derivation_distribution_counts
+ORDER BY id DESC")))))
+
+  (n-par-for-each
+   4
+   (lambda (revision-id)
+     (simple-format #t "backfilling guix_revision_package_derivation_distribution_counts for revision ~A\n" revision-id)
+     (with-thread-postgresql-connection
+      (lambda (conn)
+        (with-postgresql-transaction
+         conn
+         (lambda (conn)
+           (insert-guix-revision-package-derivation-distribution-counts
+            conn
+            revision-id))))))
+   revision-ids))
+
+(define* (get-sql-to-select-package-and-related-derivations-for-revision
+          conn
+          guix-revision-id
+          #:key system-id target)
+  (define level-counts
+    (map
+     (match-lambda
+       ((level count)
+        (list
+         (string->number level)
+         (string->number count))))
+     (exec-query
+      conn
+      "
+SELECT level, distinct_derivations
+FROM guix_revision_package_derivation_distribution_counts
+WHERE guix_revision_id = $1
+  AND system_id = $2
+  AND target = $3
+ORDER BY level ASC"
+      (list guix-revision-id
+            (number->string system-id)
+            target))))
+
+  (define (query level-counts)
+    (string-append
+     (simple-format
+      #f
+      "
+WITH l0 AS (
+  SELECT derivation_id
+  FROM package_derivations
+  INNER JOIN guix_revision_package_derivations
+    ON package_derivations.id
+        = guix_revision_package_derivations.package_derivation_id
+  WHERE revision_id = ~A
+    AND system_id = ~A
+    AND target = $STR$~A$STR$
+  LIMIT ~A
+)"
+      guix-revision-id
+      system-id
+      target
+      (cdr (car level-counts)))
+     (string-join
+      (map
+       (match-lambda*
+         ((level count)
+          (simple-format
+           #f
+           ", l~A AS (
+  (
+    SELECT derivation_outputs.derivation_id
+    FROM derivation_outputs WHERE derivation_outputs.id IN (
+      SELECT DISTINCT derivation_inputs.derivation_output_id
+      FROM l~A
+      INNER JOIN derivation_inputs
+        ON l~A.derivation_id = derivation_inputs.derivation_id
+    )
+  ) EXCEPT (~A
+  )~A
+)"
+           level
+           (- level 1)
+           (- level 1)
+           (string-join
+            (map
+             (lambda (level)
+               (simple-format
+                #f
+                "      SELECT derivation_id FROM l~A"
+                level))
+             (iota level))
+            "
+    UNION ALL")
+           (simple-format
+            #f
+            "
+  LIMIT ~A"
+            count))))
+       (iota (- (length level-counts) 1) 1)
+       (cdr (map cdr level-counts)))
+      "")
+     ", all_derivations AS (
+  SELECT *
+  FROM l0"
+     (string-join
+      (map (lambda (level)
+             (simple-format #f "  UNION (SELECT * FROM l~A)" level))
+           (iota (- (length level-counts) 1) 1))
+      "\n")
+     "
+)"))
+
+  (if level-counts
+      (query level-counts)
+      #f))
diff --git a/scripts/guix-data-service.in b/scripts/guix-data-service.in
index 7653562..d8b9b5a 100644
--- a/scripts/guix-data-service.in
+++ b/scripts/guix-data-service.in
@@ -37,6 +37,7 @@
              (guix-data-service config)
              (guix-data-service database)
              (guix-data-service substitutes)
+             (guix-data-service model guix-revision-package-derivation)
              (guix-data-service web server)
              (guix-data-service web controller)
              (guix-data-service web nar controller))
@@ -217,6 +218,13 @@
 
            (pid-file (assq-ref opts 'pid-file)))
 
+      (call-with-new-thread
+       (lambda ()
+         (with-postgresql-connection-per-thread
+          "backfill"
+          (lambda ()
+            (backfill-guix-revision-package-derivation-distribution-counts)))))
+
       (when pid-file
         (call-with-output-file pid-file
           (lambda (port)
diff --git a/sqitch/deploy/guix_revision_package_derivation_distribution_counts.sql b/sqitch/deploy/guix_revision_package_derivation_distribution_counts.sql
new file mode 100644
index 0000000..58829c5
--- /dev/null
+++ b/sqitch/deploy/guix_revision_package_derivation_distribution_counts.sql
@@ -0,0 +1,13 @@
+-- Deploy guix-data-service:guix_revision_package_derivation_distribution_counts to pg
+
+BEGIN;
+
+CREATE TABLE guix_revision_package_derivation_distribution_counts (
+  guix_revision_id integer NOT NULL REFERENCES guix_revisions (id),
+  system_id integer NOT NULL REFERENCES systems (id),
+  target varchar NOT NULL,
+  level integer NOT NULL,
+  distinct_derivations integer NOT NULL
+);
+
+COMMIT;
diff --git a/sqitch/revert/guix_revision_package_derivation_distribution_counts.sql b/sqitch/revert/guix_revision_package_derivation_distribution_counts.sql
new file mode 100644
index 0000000..7956b30
--- /dev/null
+++ b/sqitch/revert/guix_revision_package_derivation_distribution_counts.sql
@@ -0,0 +1,7 @@
+-- Revert guix-data-service:guix_revision_package_derivation_distribution_counts from pg
+
+BEGIN;
+
+-- XXX Add DDLs here.
+
+COMMIT;
diff --git a/sqitch/sqitch.plan b/sqitch/sqitch.plan
index 64b2189..caab662 100644
--- a/sqitch/sqitch.plan
+++ b/sqitch/sqitch.plan
@@ -93,3 +93,4 @@ blocked_builds 2022-11-07T11:27:28Z Chris <chris@felis> # Add blocked_builds
 package_derivations_extended_statistics 2022-11-12T10:40:18Z Chris <chris@felis> # Add extended statistics on package_derivations
 derivation_outputs_id_and_derivation_id_idx 2022-11-12T10:41:42Z Chris <chris@felis> # Add index on derivation_outputs id and derivation_id
 blocked_builds_blocked_builds_blocked_derivation_output_details_set_id_2 2023-03-05T10:19:53Z Chris <chris@felis> # Add index on blocked_builds_blocked_derivation_output_details_set_id
+guix_revision_package_derivation_distribution_counts 2023-03-08T16:53:44Z Chris <chris@felis> # Add guix_revision_package_derivation_distribution_counts table
diff --git a/sqitch/verify/guix_revision_package_derivation_distribution_counts.sql b/sqitch/verify/guix_revision_package_derivation_distribution_counts.sql
new file mode 100644
index 0000000..1f7edd2
--- /dev/null
+++ b/sqitch/verify/guix_revision_package_derivation_distribution_counts.sql
@@ -0,0 +1,7 @@
+-- Verify guix-data-service:guix_revision_package_derivation_distribution_counts on pg
+
+BEGIN;
+
+-- XXX Add verifications here.
+
+ROLLBACK;