diff --git a/guix-data-service/jobs/load-new-guix-revision.scm b/guix-data-service/jobs/load-new-guix-revision.scm
index 3bb99a6..6ef6d63 100644
--- a/guix-data-service/jobs/load-new-guix-revision.scm
+++ b/guix-data-service/jobs/load-new-guix-revision.scm
@@ -2631,21 +2631,25 @@ WHERE builder != 'builtin:download'
                  (loop (+ start-index chunk-size))))))
          derivations-vector)))
 
+    (define derivation-file-names->derivation-ids/parallelism-limiter
+      (make-parallelism-limiter 2))
     (define (process-system-and-target system target)
       (with-time-logging
           (simple-format #f "processing derivations for ~A" (cons system target))
         (let* ((derivations-vector (get-derivations system target))
                (derivation-ids
-                (with-time-logging
-                    (simple-format #f "derivation-file-names->derivation-ids (~A ~A)"
-                                   system target)
-                  (derivation-file-names->derivation-ids
-                   postgresql-connection-pool
-                   call-with-utility-thread
-                   read-derivations/serialised
-                   derivation-ids-hash-table
-                   derivations-vector
-                   #:log-tag (simple-format #f "~A:~A" system target))))
+                (with-parallelism-limiter
+                 derivation-file-names->derivation-ids/parallelism-limiter
+                 (with-time-logging
+                     (simple-format #f "derivation-file-names->derivation-ids (~A ~A)"
+                                    system target)
+                   (derivation-file-names->derivation-ids
+                    postgresql-connection-pool
+                    call-with-utility-thread
+                    read-derivations/serialised
+                    derivation-ids-hash-table
+                    derivations-vector
+                    #:log-tag (simple-format #f "~A:~A" system target)))))
                (guix-revision-id
                 (fibers-force guix-revision-id-promise))
                (package-ids (fibers-force package-ids-promise))