Auto merge of #1996 - bruceadams:no-trigger-during-import, r=smarnach

Disable database triggers during import

- This allows `updated_at` field values to be loaded during import.
  Before this change, `updated_at` was set to when the import ran,
  overwriting the values being loaded.
- Also, the import completes in about one fifth the time
  (on my slow MacBook Air).

Author: bors

src/tasks/dump_db/dump-import.sql.hbs

@@ -1,4 +1,9 @@
 BEGIN;
+    -- Disable triggers on each table.
+{{~#each tables}}
+    ALTER TABLE "{{this.name}}" DISABLE TRIGGER ALL;
+{{~/each}}
+
     -- Set defaults for non-nullable columns not included in the dump.
 {{~#each tables as |table|}}
 {{~#each column_defaults}}
@@ -21,5 +26,10 @@ BEGIN;
 {{~#each column_defaults}}
     ALTER TABLE "{{table.name}}" ALTER COLUMN "{{@key}}" DROP DEFAULT;
 {{~/each}}
+{{~/each}}
+
+    -- Reenable triggers on each table.
+{{~#each tables}}
+    ALTER TABLE "{{this.name}}" ENABLE TRIGGER ALL;
 {{~/each}}
 COMMIT;