Comment out update query in migration script due to run length concerns on a large existing database.

apps/explorer/priv/repo/migrations/20181106152300_add_nonce_to_addresses.exs

@@ -0,0 +1,31 @@
+defmodule Explorer.Repo.Migrations.AddNonceToAddresses do
+  use Ecto.Migration
+
+  def up do
+    # Add nonce
+    alter table(:addresses) do
+      add(:nonce, :integer)
+    end
+
+    # Populate nonce field from transactions table
+    # Commented out due to running time concerns
+    # execute("""
+    #     WITH t AS (
+    #         SELECT from_address_hash AS hash, MAX(nonce) AS nonce
+    #         FROM transactions
+    #         GROUP BY hash
+    #     )
+    #  UPDATE addresses AS a
+    #     SET nonce = t.nonce
+    #     FROM t
+    #     WHERE a.hash = t.hash
+    # """)
+  end
+
+  def down do
+    # Remove nonce
+    alter table(:addresses) do
+      remove(:nonce)
+    end
+  end
+end

apps/explorer/priv/repo/migrations/201811061523_add_nonce_to_addresses.exs

@@ -1,30 +0,0 @@
-defmodule Explorer.Repo.Migrations.AddNonceToAddresses do
-  use Ecto.Migration
-
-  def up do
-    # Add nonce
-    alter table(:addresses) do
-      add(:nonce, :integer)
-    end
-
-    # Populate nonce field from transactions table
-    execute("""
-        WITH t AS (
-            SELECT from_address_hash AS hash, MAX(nonce) AS nonce
-            FROM transactions
-            GROUP BY hash
-        )
-     UPDATE addresses AS a
-        SET nonce = t.nonce
-        FROM t
-        WHERE a.hash = t.hash
-    """)
-  end
-
-  def down do
-    # Remove nonce
-    alter table(:addresses) do
-      remove(:nonce)
-    end
-  end
-end