From 36b3f2af78d4e8f901b66379b816ab6f685ef45c Mon Sep 17 00:00:00 2001
From: Tim Mecklem <timothy@mecklem.com>
Date: Mon, 25 Jun 2018 13:29:51 -0400
Subject: [PATCH] Remove unused skipped blocks query from
 `Expolorer.Chain.Statistics`

---
 apps/explorer/lib/explorer/chain/statistics.ex        | 11 -----------
 apps/explorer/test/explorer/chain/statistics_test.exs |  9 ---------
 2 files changed, 20 deletions(-)

diff --git a/apps/explorer/lib/explorer/chain/statistics.ex b/apps/explorer/lib/explorer/chain/statistics.ex
index 23af3b1eb4..2a09b864af 100644
--- a/apps/explorer/lib/explorer/chain/statistics.ex
+++ b/apps/explorer/lib/explorer/chain/statistics.ex
@@ -27,13 +27,6 @@ defmodule Explorer.Chain.Statistics do
       WHERE blocks.timestamp > NOW() - interval '1 day'
   """
 
-  @skipped_blocks_query """
-    SELECT COUNT(missing_number)
-      FROM generate_series(0, $1, 1) AS missing_number
-      LEFT JOIN blocks ON missing_number = blocks.number
-      WHERE blocks.hash IS NULL
-  """
-
   @lag_query """
     SELECT coalesce(avg(lag), interval '0 seconds')
     FROM (
@@ -74,7 +67,6 @@ defmodule Explorer.Chain.Statistics do
      (`t:Explorer.Chain.Block.t/0` `timestamp`) and when it was inserted into the databasse
      (`t:Explorer.Chain.Block.t/0` `inserted_at`)
    * `number` - the latest `t:Explorer.Chain.Block.t/0` `number`
-   * `skipped_blocks` - the number of blocks that were mined/validated, but do not exist as
      `t:Explorer.Chain.Block.t/0`
    * `timestamp` - when the last `t:Explorer.Chain.Block.t/0` was mined/validated
    * `transaction_count` - the number of transactions confirmed in blocks that were mined/validated in the last day
@@ -87,7 +79,6 @@ defmodule Explorer.Chain.Statistics do
           blocks: [Block.t()],
           lag: Duration.t(),
           number: Block.block_number(),
-          skipped_blocks: non_neg_integer(),
           timestamp: :calendar.datetime(),
           transaction_count: non_neg_integer(),
           transaction_velocity: transactions_per_minute(),
@@ -99,7 +90,6 @@ defmodule Explorer.Chain.Statistics do
             blocks: [],
             lag: %Duration{seconds: 0, megaseconds: 0, microseconds: 0},
             number: -1,
-            skipped_blocks: 0,
             timestamp: nil,
             transaction_count: 0,
             transaction_velocity: 0,
@@ -142,7 +132,6 @@ defmodule Explorer.Chain.Statistics do
         %__MODULE__{
           state
           | number: number,
-            skipped_blocks: query_value(@skipped_blocks_query, [number]),
             timestamp: timestamp
         }
 
diff --git a/apps/explorer/test/explorer/chain/statistics_test.exs b/apps/explorer/test/explorer/chain/statistics_test.exs
index 1338a3b2e5..342698e009 100644
--- a/apps/explorer/test/explorer/chain/statistics_test.exs
+++ b/apps/explorer/test/explorer/chain/statistics_test.exs
@@ -60,15 +60,6 @@ defmodule Explorer.Chain.StatisticsTest do
       assert %Statistics{transaction_count: 1} = Statistics.fetch()
     end
 
-    test "returns the number of skipped blocks" do
-      insert(:block, %{number: 0})
-      insert(:block, %{number: 2})
-
-      statistics = Statistics.fetch()
-
-      assert statistics.skipped_blocks == 1
-    end
-
     test "returns the lag between validation and insertion time" do
       validation_time = DateTime.utc_now()
       inserted_at = validation_time |> Timex.shift(seconds: 5)