Merge ~cjwatson/launchpad:db-xpph-datepublished into launchpad:master

[Colin Watson]

Add xPPH indexes where datepublished is NULL

These will be useful for upcoming publisher changes that use `datepublished IS NULL` rather than `status = PENDING` to decide whether publication records need to have their files published to disk.

[William Grant (wgrant)]

Do we also need some that include distroseries?

review: Approve (db)

[Colin Watson (cjwatson)]

I can't currently think of a reason to add ones with distroseries. These indexes will be used by (I believe only) Publisher.getPendingSourcePublications, Publisher.getPendingBinaryPublications, and PublishFTPMaster.getDirtySuites. The first only uses distroseries for ordering; the second joins distroarchseries and then again only uses it for ordering; and the third doesn't pass distroseries/distroarchseries to archive.getPublishedSources/archive.getAllPublishedBinaries.

Unless you think that archive.getPublishedSources and archive.getAllPublishedBinaries would be landmines without distroseries-based indexes to support potential uses of them with both distro(arch)series and only_unpublished=True (my upcoming replacement for status=PENDING)?

diff --git a/database/schema/patch-2210-13-1.sql b/database/schema/patch-2210-13-1.sql
new file mode 100644
index 0000000..b054b18
--- /dev/null
+++ b/database/schema/patch-2210-13-1.sql
@@ -0,0 +1,13 @@
+-- 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;
+
+CREATE INDEX sourcepackagepublishinghistory__archive__status__datepublished__idx
+    ON SourcePackagePublishingHistory (archive, status)
+    WHERE datepublished IS NULL;
+CREATE INDEX binarypackagepublishinghistory__archive__status__datepublished__idx
+    ON BinaryPackagePublishingHistory (archive, status)
+    WHERE datepublished IS NULL;
+
+INSERT INTO LaunchpadDatabaseRevision VALUES (2210, 13, 1);