Backport various EE changes to Gitlab::Database

These changes are useful for CE as well. For example, the MR
https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/20720 can make
use of some of the backported methods.

1 files changed, 26 insertions, 0 deletions

diff --git a/lib/gitlab/database.rb b/lib/gitlab/database.rb
index 872e70f9a5d..8eacad078c8 100644
--- a/lib/gitlab/database.rb
+++ b/lib/gitlab/database.rb
@@ -61,6 +61,10 @@ module Gitlab
       @version ||= database_version.match(/\A(?:PostgreSQL |)([^\s]+).*\z/)[1]
     end
 
+    def self.postgresql_9_or_less?
+      postgresql? && version.to_f < 10
+    end
+
     def self.join_lateral_supported?
       postgresql? && version.to_f >= 9.3
     end
@@ -69,6 +73,28 @@ module Gitlab
       postgresql? && version.to_f >= 9.4
     end
 
+    def self.pg_stat_wal_receiver_supported?
+      postgresql? && version.to_f >= 9.6
+    end
+
+    # map some of the function names that changed between PostgreSQL 9 and 10
+    # https://wiki.postgresql.org/wiki/New_in_postgres_10
+    def self.pg_wal_lsn_diff
+      Gitlab::Database.postgresql_9_or_less? ? 'pg_xlog_location_diff' : 'pg_wal_lsn_diff'
+    end
+
+    def self.pg_current_wal_insert_lsn
+      Gitlab::Database.postgresql_9_or_less? ? 'pg_current_xlog_insert_location' : 'pg_current_wal_insert_lsn'
+    end
+
+    def self.pg_last_wal_receive_lsn
+      Gitlab::Database.postgresql_9_or_less? ? 'pg_last_xlog_receive_location' : 'pg_last_wal_receive_lsn'
+    end
+
+    def self.pg_last_wal_replay_lsn
+      Gitlab::Database.postgresql_9_or_less? ? 'pg_last_xlog_replay_location' : 'pg_last_wal_replay_lsn'
+    end
+
     def self.nulls_last_order(field, direction = 'ASC')
       order = "#{field} #{direction}"