From f71228884cb111208aa3d3aba45e344ceb691cc2 Mon Sep 17 00:00:00 2001
From: Andrew Cravenho <andrew@cravenho.me>
Date: Tue, 29 Jan 2019 11:58:48 -0500
Subject: [PATCH] Update migration script for dropped/replaced transactions

---
 .../scripts/update_replaced_transaction.sql   | 75 ++++++++++++++++++-
 1 file changed, 71 insertions(+), 4 deletions(-)

diff --git a/apps/explorer/priv/repo/migrations/scripts/update_replaced_transaction.sql b/apps/explorer/priv/repo/migrations/scripts/update_replaced_transaction.sql
index 16f0765744..78c83865df 100644
--- a/apps/explorer/priv/repo/migrations/scripts/update_replaced_transaction.sql
+++ b/apps/explorer/priv/repo/migrations/scripts/update_replaced_transaction.sql
@@ -1,19 +1,86 @@
 DO $$
   DECLARE
+    total_count         integer                     := 0;
+    completed_count     integer                     := 0;
+    remaining_count     integer                     := 0;
+    batch_size          integer                     := 1000;
+    iterator            integer                     := batch_size;
+    updated_count       integer;
+    deleted_count       integer;
     start_time          TIMESTAMP WITHOUT TIME ZONE := clock_timestamp();
     end_time            TIMESTAMP WITHOUT TIME ZONE;
     elapsed_time        INTERVAL;
     temp_start_time     TIMESTAMP WITHOUT TIME ZONE;
     temp_end_time       TIMESTAMP WITHOUT TIME ZONE;
+    temp_elapsed_time   INTERVAL;
+    update_start_time   TIMESTAMP WITHOUT TIME ZONE;
+    update_end_time     TIMESTAMP WITHOUT TIME ZONE;
+    update_elapsed_time INTERVAL;
+    per_row             INTERVAL;
   BEGIN
     RAISE NOTICE 'Started at %', start_time;
 
     temp_start_time := clock_timestamp();
 
-    UPDATE transactions SET error = 'dropped/replaced', status = 0 FROM transactions t1
-    INNER JOIN transactions t2
-    ON t1.from_address_hash = t2.from_address_hash AND t1.nonce = t2.nonce
-    WHERE t1.block_hash IS NULL AND t2.block_hash IS NOT NULL;
+    DROP TABLE IF EXISTS transactions_dropped_replaced;
+    CREATE TEMP TABLE transactions_dropped_replaced
+    (
+      nonce integer NOT NULL,
+      from_address_hash bytea NOT NULL,
+      row_number integer NOT NULL
+    );
+
+    INSERT INTO transactions_dropped_replaced
+    SELECT transactions.nonce,
+          transactions.from_address_hash,
+           ROW_NUMBER() OVER ()
+    FROM transactions
+    WHERE transactions.block_hash IS NULL;
+
+    temp_end_time := clock_timestamp();
+    temp_elapsed_time := temp_end_time - temp_start_time;
+    total_count := (SELECT COUNT(*) FROM transactions_dropped_replaced);
+
+    RAISE NOTICE 'transactions_dropped_replaced TEMP table filled in %', temp_elapsed_time;
+
+    remaining_count := total_count;
+
+    RAISE NOTICE '% transactions to be updated', remaining_count;
+
+    update_start_time := clock_timestamp();
+
+    WHILE remaining_count > 0
+      LOOP
+        UPDATE transactions
+        SET error = 'dropped/replaced', status = 0
+        FROM transactions_dropped_replaced
+        WHERE transactions_dropped_replaced.row_number <= iterator AND
+              transactions_dropped_replaced.nonce = transactions.nonce AND
+              transactions_dropped_replaced.from_address_hash = transactions.from_address_hash AND
+              transactions.block_hash IS NOT NULL;
+
+        GET DIAGNOSTICS updated_count = ROW_COUNT;
+        RAISE NOTICE '-> % transaction counts updated.', updated_count;
+
+        DELETE
+        FROM transactions_dropped_replaced
+        WHERE transactions_dropped_replaced.row_number <= iterator;
+
+        GET DIAGNOSTICS deleted_count = ROW_COUNT;
+        RAISE NOTICE '-> % transactions from it count removed from queue.', deleted_count;
+
+        -- COMMITS THE BATCH UPDATES
+        CHECKPOINT;
+
+        remaining_count := remaining_count - deleted_count;
+        iterator := iterator + batch_size;
+        RAISE NOTICE '-> % remaining', remaining_count;
+        RAISE NOTICE '-> % next batch', iterator;
+        update_elapsed_time := clock_timestamp() - update_start_time;
+        completed_count := total_count - remaining_count;
+        per_row := update_elapsed_time / completed_count;
+        RAISE NOTICE '-> Estimated time until completion: %s', per_row * remaining_count;
+      END LOOP;
 
     end_time := clock_timestamp();
     elapsed_time := end_time - start_time;