Include a db migration

deployment/hasura/migrations/Aerie/8_span_event_linkage/down.sql

@@ -0,0 +1,11 @@
+-- event table revert
+alter table merlin.event
+  drop column span_index;
+
+-- span table revert
+alter table merlin.span
+  drop constraint dataset_span_index_unique;
+
+alter table merlin.span
+  drop column span_index;
+

deployment/hasura/migrations/Aerie/8_span_event_linkage/up.sql

@@ -0,0 +1,15 @@
+-- Span Table update
+alter table merlin.span
+  add column span_index integer;
+
+update merlin.span
+set span_index = id;
+
+alter table merlin.span
+  alter column span_index set not null,
+  add constraint dataset_span_index_unique
+    unique (dataset_id, span_index);
+
+-- event table update
+alter table merlin.event
+  add column span_index integer not null;