diff --git a/schema.surql b/schema.surql
index c39e278..58d4f3d 100644
--- a/schema.surql
+++ b/schema.surql
@@ -1,9 +1,14 @@
+DELETE website;
+DELETE links_to;
+DELETE url_index;
+
 DEFINE TABLE website SCHEMAFULL;
-    DEFINE FIELD accessed_at ON TABLE website TYPE datetime DEFAULT time::now();
+    DEFINE FIELD accessed_at ON TABLE website VALUE time::now();
     DEFINE FIELD crawled     ON TABLE website TYPE bool DEFAULT false;
     DEFINE FIELD url         ON TABLE website TYPE string;
     DEFINE FIELD domain      ON TABLE website VALUE parse::url::domain($this.url) ASSERT !type::is::none($value);
     DEFINE FIELD path        ON TABLE website VALUE parse::url::path($this.url) ASSERT !type::is::none($value);
+    DEFINE INDEX url_index   ON TABLE website COLUMNS url UNIQUE;
 
 DEFINE TABLE links_to SCHEMAFULL TYPE RELATION FROM website TO website;
     DEFINE FIELD discovered_at ON TABLE links_to TYPE datetime DEFAULT time::now();