diff --git a/crates/util/cometindex/vendor/schema.sql b/crates/util/cometindex/vendor/schema.sql
index ce5a241bad..fd78e677e0 100644
--- a/crates/util/cometindex/vendor/schema.sql
+++ b/crates/util/cometindex/vendor/schema.sql
@@ -65,6 +65,9 @@ CREATE TABLE attributes (
    UNIQUE (event_id, key)
 );
 
+-- To make it efficient to fetch the attributes of a given event.
+CREATE INDEX ON attributes(event_id);
+
 -- A joined view of events and their attributes. Events that do not have any
 -- attributes are represented as a single row with empty key and value fields.
 CREATE VIEW event_attributes AS