Merge pull request #339 from poanetwork/more-homepage-query-optimizations-#330

More home page query optimizations

apps/explorer/lib/explorer/chain/statistics.ex

@@ -19,24 +19,8 @@ defmodule Explorer.Chain.Statistics do
     ) t
   """
 
-  @lag_query """
-    SELECT coalesce(avg(lag), interval '0 seconds')
-    FROM (
-      SELECT inserted_at - timestamp AS lag
-      FROM blocks
-      WHERE blocks.inserted_at > NOW() - interval '1 hour'
-        AND blocks.timestamp > NOW() - interval '1 hour'
-    ) t
-  """
-
-  @block_velocity_query """
-    SELECT count(blocks.hash)
-      FROM blocks
-      WHERE blocks.inserted_at > NOW() - interval '1 minute'
-  """
-
   @transaction_velocity_query """
-    SELECT count(transactions.hash)
+    SELECT count(transactions.inserted_at)
       FROM transactions
       WHERE transactions.inserted_at > NOW() - interval '1 minute'
   """
@@ -53,9 +37,7 @@ defmodule Explorer.Chain.Statistics do
 
   @typedoc """
    * `average_time` - the average time it took to mine/validate the last <= 100 `t:Explorer.Chain.Block.t/0`
-   * `block_velocity` - the number of `t:Explorer.Chain.Block.t/0` mined/validated in the last minute
    * `blocks` - the last <= 5 `t:Explorer.Chain.Block.t/0`
-   * `lag` - the average time over the last hour between when the block was mined/validated
      (`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`
@@ -66,9 +48,7 @@ defmodule Explorer.Chain.Statistics do
   """
   @type t :: %__MODULE__{
           average_time: Duration.t(),
-          block_velocity: blocks_per_minute(),
           blocks: [Block.t()],
-          lag: Duration.t(),
           number: Block.block_number(),
           timestamp: :calendar.datetime(),
           transaction_velocity: transactions_per_minute(),
@@ -76,9 +56,7 @@ defmodule Explorer.Chain.Statistics do
         }
 
   defstruct average_time: %Duration{seconds: 0, megaseconds: 0, microseconds: 0},
-            block_velocity: 0,
             blocks: [],
-            lag: %Duration{seconds: 0, megaseconds: 0, microseconds: 0},
             number: -1,
             timestamp: nil,
             transaction_velocity: 0,
@@ -105,9 +83,7 @@ defmodule Explorer.Chain.Statistics do
 
     %__MODULE__{
       average_time: query_duration(@average_time_query),
-      block_velocity: query_value(@block_velocity_query),
       blocks: Repo.all(blocks),
-      lag: query_duration(@lag_query),
       transaction_velocity: query_value(@transaction_velocity_query),
       transactions: transactions
     }

apps/explorer/test/explorer/chain/statistics_test.exs

@@ -45,24 +45,6 @@ defmodule Explorer.Chain.StatisticsTest do
              } = Statistics.fetch()
     end
 
-    test "returns the lag between validation and insertion time" do
-      validation_time = DateTime.utc_now()
-      inserted_at = validation_time |> Timex.shift(seconds: 5)
-      insert(:block, timestamp: validation_time, inserted_at: inserted_at)
-
-      assert %Statistics{lag: %Duration{seconds: 5, megaseconds: 0, microseconds: 0}} = Statistics.fetch()
-    end
-
-    test "returns the number of blocks inserted in the last minute" do
-      old_inserted_at = Timex.shift(DateTime.utc_now(), days: -1)
-      insert(:block, inserted_at: old_inserted_at)
-      insert(:block)
-
-      statistics = Statistics.fetch()
-
-      assert statistics.block_velocity == 1
-    end
-
     test "returns the number of transactions inserted in the last minute" do
       old_inserted_at = Timex.shift(DateTime.utc_now(), days: -1)
       insert(:transaction, inserted_at: old_inserted_at)