--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/db/libervia_pubsub_update_4_5.sql	Fri Oct 15 13:40:59 2021 +0200
@@ -0,0 +1,20 @@
+-- we check version of the database before doing anything
+-- and stop execution if not good
+\set ON_ERROR_STOP
+DO $$
+DECLARE ver text;
+BEGIN
+    SELECT value INTO ver FROM metadata WHERE key='version';
+    IF NOT FOUND OR ver!='4' THEN
+        RAISE EXCEPTION 'This update file needs to be applied on database schema version 4, you use version %',ver;
+    END IF;
+END$$;
+\unset ON_ERROR_STOP
+-- end of version check
+
+/* new "max_items" and "consistent publisher" options */
+ALTER TABLE nodes ADD COLUMN max_items integer NOT NULL DEFAULT 0
+		CHECK (max_items >= 0);
+ALTER TABLE nodes ADD COLUMN consistent_publisher boolean NOT NULL DEFAULT FALSE;
+
+UPDATE metadata SET value='5' WHERE key='version';