From 86846271ff0f548116a13a4c8d25e1928507c7bf Mon Sep 17 00:00:00 2001
From: Beth Skurrie <beth@bethesque.com>
Date: Mon, 28 Oct 2019 10:16:36 +1100
Subject: [PATCH] feat: optimise latest_pact_publications_by_consumer_versions

---
 ...est_pact_publications_by_consumer_versions.rb | 16 ++++++++++++++++
 .../000028_create_all_pact_publications.rb       |  1 +
 db/migrations/20180722_recreate_views.rb         | 11 ++++-------
 ...st_pact_publications_by_consumer_versions_.rb | 13 +++++++++++++
 4 files changed, 34 insertions(+), 7 deletions(-)
 create mode 100644 db/ddl_statements/latest_pact_publications_by_consumer_versions.rb
 create mode 100644 db/migrations/20191030_optimise_latest_pact_publications_by_consumer_versions_.rb

diff --git a/db/ddl_statements/latest_pact_publications_by_consumer_versions.rb b/db/ddl_statements/latest_pact_publications_by_consumer_versions.rb
new file mode 100644
index 000000000..7fb60aded
--- /dev/null
+++ b/db/ddl_statements/latest_pact_publications_by_consumer_versions.rb
@@ -0,0 +1,16 @@
+def latest_pact_publications_by_consumer_versions_v2(connection = nil)
+  "select app.*
+  from latest_pact_publication_ids_for_consumer_versions lpp
+  inner join all_pact_publications app
+  on lpp.consumer_version_id = app.consumer_version_id
+  and lpp.pact_publication_id = app.id
+  and lpp.provider_id = app.provider_id"
+end
+
+# Don't need all the join keys, just pact_publication_id
+def latest_pact_publications_by_consumer_versions_v3(connection)
+  "select app.*
+  from latest_pact_publication_ids_for_consumer_versions lpp
+  inner join all_pact_publications app
+  on lpp.pact_publication_id = app.id"
+end
diff --git a/db/migrations/000028_create_all_pact_publications.rb b/db/migrations/000028_create_all_pact_publications.rb
index aad274757..57030e3b8 100644
--- a/db/migrations/000028_create_all_pact_publications.rb
+++ b/db/migrations/000028_create_all_pact_publications.rb
@@ -23,6 +23,7 @@
 
     # Latest pact_publication (revision) for each provider/consumer version
     # updated in 20180519_recreate_views.rb
+    # latest_pact_publications_by_consumer_versions_v1
     create_view(:latest_pact_publications_by_consumer_versions,
       "select app.*
       from all_pact_publications app
diff --git a/db/migrations/20180722_recreate_views.rb b/db/migrations/20180722_recreate_views.rb
index 900333cd3..220d9ac3d 100644
--- a/db/migrations/20180722_recreate_views.rb
+++ b/db/migrations/20180722_recreate_views.rb
@@ -1,14 +1,10 @@
+require_relative '../ddl_statements'
+
 Sequel.migration do
   up do
     # Latest pact_publication details for each provider/consumer version
     create_or_replace_view(:latest_pact_publications_by_consumer_versions,
-      "select app.*
-      from latest_pact_publication_ids_for_consumer_versions lpp
-      inner join all_pact_publications app
-      on lpp.consumer_version_id = app.consumer_version_id
-      and lpp.pact_publication_id = app.id
-      and lpp.provider_id = app.provider_id"
-    )
+      latest_pact_publications_by_consumer_versions_v2(self))
 
     # Latest consumer version order for consumer/provider
     # Recreate latest_pact_publication_ids_for_consumer_versions view
@@ -17,6 +13,7 @@
 
   down do
     # Latest pact_publication details for each provider/consumer version
+    # latest_pact_publications_by_consumer_versions_v1
     create_or_replace_view(:latest_pact_publications_by_consumer_versions,
       "select app.*
       from all_pact_publications app
diff --git a/db/migrations/20191030_optimise_latest_pact_publications_by_consumer_versions_.rb b/db/migrations/20191030_optimise_latest_pact_publications_by_consumer_versions_.rb
new file mode 100644
index 000000000..243038a82
--- /dev/null
+++ b/db/migrations/20191030_optimise_latest_pact_publications_by_consumer_versions_.rb
@@ -0,0 +1,13 @@
+require_relative '../ddl_statements'
+
+Sequel.migration do
+  up do
+    create_or_replace_view(:latest_pact_publications_by_consumer_versions,
+      latest_pact_publications_by_consumer_versions_v3(self))
+  end
+
+  down do
+    create_or_replace_view(:latest_pact_publications_by_consumer_versions,
+      latest_pact_publications_by_consumer_versions_v2(self))
+  end
+end