yoku0825

mysql80 15> SHOW CREATE TABLE t1\G
*************************** 1. row ***************************
       Table: t1
Create Table: CREATE TABLE `t1` (
  `num` bigint unsigned NOT NULL AUTO_INCREMENT /*!80023 INVISIBLE */,
  `val` varchar(32) COLLATE utf8mb4_ja_0900_as_cs DEFAULT NULL,
  UNIQUE KEY `num` (`num`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_ja_0900_as_cs
1 row in set (0.00 sec)

yoku0825

master [localhost] {msandbox} ((none)) > ALTER TABLE d1.t1 ADD dummy_uuid VARCHAR(36) DEFAULT NULL UNIQUE;
Query OK, 0 rows affected (0.03 sec)
Records: 0  Duplicates: 0  Warnings: 0

master [localhost] {msandbox} ((none)) > INSERT INTO d1.t1 VALUES (3, UUID());
Query OK, 1 row affected (0.00 sec)

$ ./use_all -e "SELECT * FROM d1.t1"
# master
num     dummy_uuid

yoku0825

[mysqld]
binlog_row_image = MINIMAL                            ### バイナリログのエントリあたりの容量を削減
default_authentication_plugin = mysql_native_password ### 5.7, MariaDBとかから載せ替えるなら
event_scheduler = OFF                                 ### 使ってなければお好みで。メモリリークあり
information_schema_stats_expiry = 0                   ### SHOW TABLE STATUSが更新されない件
innodb_buffer_pool_size = ?
skip-innodb_doublewrite                               ### 永続性そっちのけならアリ
innodb_flush_log_at_trx_commit = 2                    ### 実はこれより ALTER INSTANCE DISABLE INNODB REDO_LOGの方が効く。ALTER INSTANCE .. はib_logfileに書き込まれるので対応するオプションはない。あと、正常終了しなかったときに二度と起動しなくなる
innodb_flush_method = O_DIRECT_NO_FSYNC
innodb_log_writer_threads = OFF  ### もしCPU性能が低いVMとかの場合、これをOFFにするとちょっと速くなることがある

yoku0825

----system---- ----total-cpu-usage---- -dsk/total- -net/total- ---paging-- ---system-- ------memory-usage----- --io/total- ---load-avg---
     time     |usr sys idl wai hiq siq| read  writ| recv  send|  in   out | int   csw | used  buff  cach  free| read  writ| 1m   5m  15m
21-02 10:01:24|  3   0  96   1   0   0|   0  5998k| 567k 1127k|   0     0 |3088  5277 |6573M 2392k 48.2G 8303M|   0   373 |0.19 0.16 0.19
21-02 10:01:25|  2   0  96   1   0   0|   0  8285k| 425k  847k|   0     0 |2847  4928 |6573M 2392k 48.2G 8299M|   0   329 |0.19 0.16 0.19

yoku0825

#!/usr/bin/perl

use strict;
use warnings;
use utf8;

my $file= "./general_query.log";
open(my $fh, "<", $file) or die;

yoku0825

mysql80 26> SELECT x'E8919BF3A08481', LENGTH(x'E8919BF3A08481'), CHARACTER_LENGTH(x'E8919BF3A08481');
+-------------------+---------------------------+-------------------------------------+
| x'E8919BF3A08481' | LENGTH(x'E8919BF3A08481') | CHARACTER_LENGTH(x'E8919BF3A08481') |
+-------------------+---------------------------+-------------------------------------+
| 葛󠄁                |                         7 |                                   7 |
+-------------------+---------------------------+-------------------------------------+
1 row in set (0.00 sec)

yoku0825

$ ll /usr/mysql/5.7.36/data/d1/
total 220
-rw-r----- 1 yoku0825 yoku0825    67 Nov 15 17:50 db.opt
-rw-r----- 1 yoku0825 yoku0825  8586 Nov 15 17:57 t1.frm
-rw-r----- 1 yoku0825 yoku0825 98304 Nov 15 17:57 t1.ibd          <--- innodb_file_per_table= ON
-rw-r----- 1 yoku0825 yoku0825  8586 Nov 15 17:56 t3.frm
-rw-r----- 1 yoku0825 yoku0825 98304 Nov 15 17:56 t3.ibd


mysql57 11> SET GLOBAL innodb_file_per_table= 0;

yoku0825

<?php

function t2_in_1_3($buff)
{
  if ($buff["t2"] == 1 || $buff["t2"] == 3)
    return true;
  return false;
}

$t1= array(1, 2, 3);

yoku0825

mysql> SELECT @@version;
+-----------+
| @@version |
+-----------+
| 8.0.25    |
+-----------+
1 row in set (0.00 sec)

mysql> SHOW GRANTS;
+--------------------------------------+

yoku0825

Breakpoint 1, Parallel_reader::parallel_read() () at /home/yoku0825/mysql-8.0.26/storage/innobase/row/row0pread.cc:1087
1087    void Parallel_reader::parallel_read() {
(gdb) c
+c
Continuing.
[New Thread 0x7f2972ffd700 (LWP 1916)]
[New Thread 0x7f2971ffb700 (LWP 1917)]
[New Thread 0x7f2998ff9700 (LWP 1914)]
[New Thread 0x7f296b7fe700 (LWP 1920)]
[New Thread 0x7f2970ff9700 (LWP 1918)]