dougal-software/etc/db/upgrades/upgrade43-v0.6.5-add-comparisons-notification-channel.sql

-- Add procedure to decimate old nav data
--
-- New schema version: 0.6.5
--
-- ATTENTION:
--
-- ENSURE YOU HAVE BACKED UP THE DATABASE BEFORE RUNNING THIS SCRIPT.
--
--
-- NOTE: This upgrade affects the public schema only.
-- NOTE: Each application starts a transaction, which must be committed
-- or rolled back.
--
-- This update modifies notify() to accept, as optional arguments, the
-- names of columns that are to be *excluded* from the notification.
-- It is intended for tables with large columns which are however of
-- no particular interest in a notification.
--
-- To apply, run as the dougal user:
--
-- psql <<EOF
-- \i $THIS_FILE
-- COMMIT;
-- EOF
--
-- NOTE: It can be applied multiple times without ill effect.
--

BEGIN;

CREATE OR REPLACE PROCEDURE pg_temp.show_notice (notice text) AS $$
BEGIN
	RAISE NOTICE '%', notice;
END;
$$ LANGUAGE plpgsql;

CREATE OR REPLACE PROCEDURE pg_temp.upgrade_database () AS $outer$
BEGIN

	RAISE NOTICE 'Updating schema %', 'public';
	SET search_path TO public;

	-- BEGIN

	CREATE OR REPLACE TRIGGER comparisons_tg
		AFTER INSERT OR DELETE OR UPDATE
		ON comparisons.comparisons
		FOR EACH ROW
		EXECUTE FUNCTION public.notify('comparisons', 'data');

	-- END

END;
$outer$ LANGUAGE plpgsql;

CREATE OR REPLACE PROCEDURE pg_temp.upgrade () AS $outer$
DECLARE
	row RECORD;
	current_db_version TEXT;
BEGIN

	SELECT value->>'db_schema' INTO current_db_version FROM public.info WHERE key = 'version';

	IF current_db_version >= '0.6.5' THEN
		RAISE EXCEPTION
			USING MESSAGE='Patch already applied';
	END IF;

	IF current_db_version != '0.6.4' THEN
		RAISE EXCEPTION
			USING MESSAGE='Invalid database version: ' || current_db_version,
				HINT='Ensure all previous patches have been applied.';
	END IF;

	CALL pg_temp.upgrade_database();
END;
$outer$ LANGUAGE plpgsql;

CALL pg_temp.upgrade();

CALL pg_temp.show_notice('Cleaning up');
DROP PROCEDURE pg_temp.upgrade_database ();
DROP PROCEDURE pg_temp.upgrade ();

CALL pg_temp.show_notice('Updating db_schema version');
INSERT INTO public.info VALUES ('version', '{"db_schema": "0.6.5"}')
ON CONFLICT (key) DO UPDATE
	SET value = public.info.value || '{"db_schema": "0.6.5"}' WHERE public.info.key = 'version';


CALL pg_temp.show_notice('All done. You may now run "COMMIT;" to persist the changes');
DROP PROCEDURE pg_temp.show_notice (notice text);

--
--NOTE Run `COMMIT;` now if all went well
--