Merge ~cjwatson/launchpad:db-distribution-traversal into launchpad:db-devel

[Colin Watson]

Add default traversal columns to Distribution

These describe how a name immediately following the distribution name in a URL is interpreted.

Since there are only a few dozen distributions in production, it doesn't seem worth going to extra effort to avoid rewriting the table.

Code MPs: https://code.launchpad.net/~cjwatson/launchpad/+git/launchpad/+merge/393731 and https://code.launchpad.net/~cjwatson/launchpad/+git/launchpad/+merge/393809

[William Grant (wgrant)]

review: Approve (db)

diff --git a/database/schema/patch-2210-23-0.sql b/database/schema/patch-2210-23-0.sql
new file mode 100644
index 0000000..d1db911
--- /dev/null
+++ b/database/schema/patch-2210-23-0.sql
@@ -0,0 +1,11 @@
+-- Copyright 2020 Canonical Ltd.  This software is licensed under the
+-- GNU Affero General Public License version 3 (see the file LICENSE).
+
+SET client_min_messages=ERROR;
+
+ALTER TABLE Distribution
+    -- 0 == SERIES
+    ADD COLUMN default_traversal_policy integer DEFAULT 0 NOT NULL,
+    ADD COLUMN redirect_default_traversal boolean DEFAULT false NOT NULL;
+
+INSERT INTO LaunchpadDatabaseRevision VALUES (2210, 23, 0);