Patched
-------
 relkind |        relname        |   nrows   | blk_before | mb_before | blk_after | mb_after |  Diff
---------+-----------------------+-----------+------------+-----------+-----------+----------+-------
 r       | pgbench_accounts      | 200000000 |    3278689 |   25614.8 |   3330788 |  26021.8 | +1.6%
 i       | accounts_mtime        | 200000000 |     770080 |    6016.3 |    806920 |   6304.1 | +4.8%
 i       | pgbench_accounts_pkey | 200000000 |     548383 |    4284.2 |    548383 |   4284.2 |    0
 i       | tenner                | 200000000 |     230701 |    1802.4 |    230701 |   1802.4 |    0
(4 rows)

scaling factor: 2000
query mode: simple
number of clients: 8
number of threads: 2
duration: 3600 s
number of transactions actually processed: 9581078
latency average = 3.006 ms
tps = 2661.408684 (including connections establishing)
tps = 2661.409851 (excluding connections establishing)
statement latencies in milliseconds:
         0.001  \set aid1 random_gaussian(1, 100000 * :scale, 2.0)
         0.001  \set aid2 random_gaussian(1, 100000 * :scale, 2.5)
         0.000  \set delta random(-5000, 5000)
         0.044  BEGIN;
         0.263  UPDATE pgbench_accounts SET abalance = abalance + :delta WHERE aid = :aid1;
         0.144  SELECT abalance FROM pgbench_accounts WHERE aid = :aid2;
         2.549  END;

scaling factor: 2000
query mode: simple
number of clients: 8
number of threads: 2
duration: 3600 s
number of transactions actually processed: 71467156
latency average = 0.403 ms
tps = 19851.985574 (including connections establishing)
tps = 19851.994168 (excluding connections establishing)
statement latencies in milliseconds:
         0.001  \set aid1 random_gaussian(1, 100000 * :scale, 2.0)
         0.001  \set aid2 random_gaussian(1, 100000 * :scale, 2.5)
         0.001  \set aid3 random_gaussian(1, 100000 * :scale, 3.2)
         0.033  BEGIN;
         0.112  SELECT abalance FROM pgbench_accounts WHERE aid = :aid1;
         0.109  SELECT abalance FROM pgbench_accounts WHERE aid = :aid2;
         0.107  SELECT abalance FROM pgbench_accounts WHERE aid = :aid3;
         0.037  END;

scaling factor: 2000
query mode: simple
number of clients: 8
number of threads: 2
duration: 3600 s
number of transactions actually processed: 14115
latency average = 2047.201 ms
tps = 3.907774 (including connections establishing)
tps = 3.907776 (excluding connections establishing)
statement latencies in milliseconds:
      2047.098  SELECT abalance FROM pgbench_accounts WHERE mtime > now() - INTERVAL '15min' ORDER BY aid;