Improve dropping package_derivation_by_guix_revision_range partitions

guix-data-service/data-deletion.scm

@@ -24,6 +24,7 @@
   #:use-module (fibers)
   #:use-module (guix-data-service utils)
   #:use-module (guix-data-service database)
+  #:use-module (guix-data-service model git-branch)
   #:use-module (guix-data-service model package-derivation-by-guix-revision-range)
   #:export (delete-guix-revisions
             delete-data-for-branch
@@ -213,18 +214,16 @@ WHERE id IN (
      (delete-from-git-commits conn)
      (delete-jobs conn)
 
-     (exec-query
-      conn
-      "
-DELETE FROM package_derivations_by_guix_revision_range
-WHERE git_branch_id IN (
-  SELECT id
-  FROM git_branches
-  WHERE git_repository_id = $1 AND
-        name = $2
-)"
-      (list (number->string git-repository-id)
-            branch-name))
+     (let ((git-branch-id
+            (git-branch-for-repository-and-name conn
+                                                git-repository-id
+                                                branch-name)))
+       (exec-query
+        conn
+        (string-append
+         "
+DROP TABLE package_derivations_by_guix_revision_range_git_branch_"
+         (number->string git-branch-id) ";")))
 
      (delete-guix-revisions conn git-repository-id commits))))