feat: optimise latest_tagged_pact_consumer_version_orders view

Author: bethesque

db/ddl_statements/latest_tagged_pact_consumer_version_orders.rb

@@ -0,0 +1,23 @@
+def latest_tagged_pact_consumer_version_orders_v2(connection)
+  pp = :pact_publications
+  connection.from(pp)
+    .select_group(
+      Sequel[pp][:provider_id],
+      Sequel[:cv][:pacticipant_id].as(:consumer_id),
+      Sequel[:t][:name].as(:tag_name))
+    .select_append{ max(order).as(latest_consumer_version_order) }
+    .join(:versions, { Sequel[pp][:consumer_version_id] => Sequel[:cv][:id] }, { table_alias: :cv} )
+    .join(:tags, { Sequel[:t][:version_id] => Sequel[pp][:consumer_version_id] }, { table_alias: :t })
+end
+
+def latest_tagged_pact_consumer_version_orders_v3(connection)
+  view = Sequel.as(:latest_pact_publication_ids_for_consumer_versions, :lp)
+  connection.from(view)
+    .select_group(
+      Sequel[:lp][:provider_id],
+      Sequel[:cv][:pacticipant_id].as(:consumer_id),
+      Sequel[:t][:name].as(:tag_name))
+    .select_append{ max(order).as(latest_consumer_version_order) }
+    .join(:versions, { Sequel[:lp][:consumer_version_id] => Sequel[:cv][:id] }, { table_alias: :cv} )
+    .join(:tags, { Sequel[:t][:version_id] => Sequel[:lp][:consumer_version_id] }, { table_alias: :t })
+end

db/migrations/20180311_optimise_head_matrix.rb

@@ -6,15 +6,7 @@
     pp = :pact_publications
     # For each consumer_id/provider_id/tag_name, the version order of the latest version that has a pact
     create_or_replace_view(:latest_tagged_pact_consumer_version_orders,
-      from(:pact_publications)
-        .select_group(
-          Sequel[pp][:provider_id],
-          Sequel[:cv][:pacticipant_id].as(:consumer_id),
-          Sequel[:t][:name].as(:tag_name))
-        .select_append{ max(order).as(latest_consumer_version_order) }
-        .join(:versions, { Sequel[pp][:consumer_version_id] => Sequel[:cv][:id] }, { table_alias: :cv} )
-        .join(:tags, { Sequel[:t][:version_id] => Sequel[pp][:consumer_version_id] }, { table_alias: :t })
-    )
+      latest_tagged_pact_consumer_version_orders_v2(self))
 
     # Add provider_version_order to original definition
     # The most recent verification for each pact_version

db/migrations/20191028_optimise_latest_tagged_pact_cv_orders.rb

@@ -0,0 +1,13 @@
+require_relative '../ddl_statements'
+
+Sequel.migration do
+  up do
+    create_or_replace_view(:latest_tagged_pact_consumer_version_orders,
+      latest_tagged_pact_consumer_version_orders_v3(self))
+  end
+
+  down do
+    create_or_replace_view(:latest_tagged_pact_consumer_version_orders,
+      latest_tagged_pact_consumer_version_orders_v2(self))
+  end
+end