--------------
update orders2 set o_orderpriority=concat('upd-', o_orderkey), o_custkey=-1 where o_orderdate <= '1992-01-31'
--------------

Query OK, 1932789 rows affected (44.88 sec)
Rows matched: 0  Changed: 0  Warnings: 0

--------------
select count(distinct o_orderpriority) from orders2 where o_orderdate <= '1992-01-31'
--------------

+---------------------------------+
| count(distinct o_orderpriority) |
+---------------------------------+
|                         1932789 |
+---------------------------------+
1 row in set (0.89 sec)

--------------
select count(*) from orders2 where o_custkey = -1
--------------

+----------+
| count(*) |
+----------+
|  1932789 |
+----------+
1 row in set (0.65 sec)

--------------
delete from orders2 where o_orderdate <= '1992-01-31'
--------------

Query OK, 1932789 rows affected (12.72 sec)

--------------
select count(*) from orders2
--------------

+----------+
| count(*) |
+----------+
| 20877570 |
+----------+
1 row in set (0.18 sec)

--------------
select count(o_orderkey) from orders2
--------------

+-------------------+
| count(o_orderkey) |
+-------------------+
|          20877570 |
+-------------------+
1 row in set (0.78 sec)

--------------
select count(o_custkey) from orders2
--------------

+------------------+
| count(o_custkey) |
+------------------+
|         20877570 |
+------------------+
1 row in set (0.86 sec)

--------------
select count(o_orderstatus) from orders2
--------------

+----------------------+
| count(o_orderstatus) |
+----------------------+
|             20877570 |
+----------------------+
1 row in set (0.15 sec)

--------------
select count(o_totalprice) from orders2
--------------

+---------------------+
| count(o_totalprice) |
+---------------------+
|            20877570 |
+---------------------+
1 row in set (1.32 sec)

--------------
select count(o_orderdate) from orders2
--------------

+--------------------+
| count(o_orderdate) |
+--------------------+
|           20877570 |
+--------------------+
1 row in set (0.34 sec)

--------------
select count(o_orderpriority) from orders2
--------------

+------------------------+
| count(o_orderpriority) |
+------------------------+
|               20877570 |
+------------------------+
1 row in set (0.43 sec)

--------------
select count(o_clerk) from orders2
--------------

+----------------+
| count(o_clerk) |
+----------------+
|       20877570 |
+----------------+
1 row in set (0.86 sec)

--------------
select count(o_shippriority) from orders2
--------------

+-----------------------+
| count(o_shippriority) |
+-----------------------+
|              20877570 |
+-----------------------+
1 row in set (0.28 sec)

--------------
select count(o_comment) from orders2
--------------

+------------------+
| count(o_comment) |
+------------------+
|         20877570 |
+------------------+
1 row in set (0.92 sec)

Bye