diff --git a/guix-data-service/model/derivation.scm b/guix-data-service/model/derivation.scm
index 37e0622..4660a4c 100644
--- a/guix-data-service/model/derivation.scm
+++ b/guix-data-service/model/derivation.scm
@@ -1105,6 +1105,25 @@ ON CONFLICT DO NOTHING"
                 (vector->list (json-string->scm env_vars)))
            system))))
 
+(define select-derivation-output-id
+  (mlambda (conn name path)
+    (match (exec-query
+            conn
+            "
+SELECT derivation_outputs.id FROM derivation_outputs
+INNER JOIN derivations
+  ON derivation_outputs.derivation_id = derivations.id
+WHERE derivations.file_name = $1
+  AND derivation_outputs.name = $2"
+            (list path
+                  name))
+      (((id))
+       id)
+      (()
+       (error (simple-format
+               #f "cannot find derivation-output with name ~A and path ~A"
+               name path))))))
+
 (define (select-derivation-outputs-by-derivation-id conn id)
   (define query
     (string-append
@@ -1377,49 +1396,42 @@ WHERE derivation_source_files.store_path = $1"
         #f)))
 
 (define (insert-derivation-inputs conn derivation-ids derivations)
-  (let ((query-parts
-         (append-map!
-          (lambda (derivation-id derivation)
-            (append-map!
-             (match-lambda
-               (($ <derivation-input> derivation-or-path sub-derivations)
-                (let ((path
-                       (match derivation-or-path
-                         ((? derivation? d)
-                          ;; The first field changed to a derivation (from the file
-                          ;; name) in 5cf4b26d52bcea382d98fb4becce89be9ee37b55
-                          (derivation-file-name d))
-                         ((? string? s)
-                          s))))
-                  (map (lambda (sub-derivation)
-                         (string-append "("
-                                        (number->string derivation-id)
-                                        ", '" path
-                                        "', '" sub-derivation "')"))
-                       sub-derivations))))
-             (derivation-inputs derivation)))
-          (vector->list derivation-ids)
-          (vector->list derivations))))
-
-    (chunk-for-each!
-     (lambda (query-parts-chunk)
+  (define (insert-into-derivation-inputs derivation-id output-ids)
+    (for-each
+     (lambda (output-id)
        (exec-query
         conn
-        (string-append
-         "
+        "
 INSERT INTO derivation_inputs (derivation_id, derivation_output_id)
-SELECT vals.derivation_id, derivation_outputs.id
-FROM (VALUES "
-         (string-join query-parts-chunk ", ")
-         ") AS vals (derivation_id, file_name, output_name)
-INNER JOIN derivations
-  ON derivations.file_name = vals.file_name
-INNER JOIN derivation_outputs
-  ON derivation_outputs.derivation_id = derivations.id
- AND vals.output_name = derivation_outputs.name
-ON CONFLICT DO NOTHING")))
-     1000
-     query-parts)))
+VALUES ($1, $2);"
+        (list (number->string derivation-id) output-id)))
+     output-ids))
+
+  (vector-for-each
+   (lambda (i derivation-id derivation)
+     (let ((inputs (derivation-inputs derivation)))
+       (unless (null? inputs)
+         (insert-into-derivation-inputs
+          derivation-id
+          (append-map!
+           (match-lambda
+             (($ <derivation-input> derivation-or-path sub-derivations)
+              (let ((path
+                     (match derivation-or-path
+                       ((? derivation? d)
+                        ;; The first field changed to a derivation (from the file
+                        ;; name) in 5cf4b26d52bcea382d98fb4becce89be9ee37b55
+                        (derivation-file-name d))
+                       ((? string? s)
+                        s))))
+                (map (lambda (sub-derivation)
+                       (select-derivation-output-id conn
+                                                    sub-derivation
+                                                    path))
+                     sub-derivations))))
+           inputs)))))
+   derivation-ids
+   derivations))
 
 (define (insert-derivation-sources conn derivation-id sources)
   (define (insert-into-derivation-sources derivation-source-file-ids)