tag_updates table for tracking non-versioned alterations

docs/schema.sql

@@ -370,6 +370,20 @@ CREATE TABLE tag_config (
 ) WITHOUT OIDS;
 
 
+-- the tag_updates table provides a mechanism to indicate changes relevant to tag
+-- that are not reflected in a versioned table. For example: builds changing volumes,
+-- changes to external repo content, additional rpms imported to an existing build
+CREATE TABLE tag_updates (
+        id SERIAL NOT NULL PRIMARY KEY,
+        tag_id INTEGER NOT NULL REFERENCES tag(id),
+        update_event INTEGER NOT NULL REFERENCES events(id) DEFAULT get_event(),
+        updater_id INTEGER NOT NULL REFERENCES users(id),
+        update_type INTEGER NOT NULL
+) WITHOUT OIDS;
+
+CREATE INDEX tag_updates_by_tag ON tag_updates (tag_id);
+CREATE INDEX tag_updates_by_event ON tag_updates (update_event);
+
 -- a build target tells the system where to build the package
 -- and how to tag it afterwards.
 CREATE TABLE build_target (