diff --git a/guix-data-service/model/derivation.scm b/guix-data-service/model/derivation.scm
index 5465054..2e0345d 100644
--- a/guix-data-service/model/derivation.scm
+++ b/guix-data-service/model/derivation.scm
@@ -1804,9 +1804,11 @@ WHERE derivation_inputs.derivation_id IN ("
 
                        number))))
              (with-time-logging
-                 "querying for batch of all related derivation ids"
+                 (simple-format
+                  #f "querying for batch of ~A related derivation ids"
+                  (length ids-chunk))
                (exec-query conn query)))))
-        (chunk! ids 2000))
+        (chunk! ids 1000))
        <))
 
     (define (derivation-ids->missing-sources ids)