mysql.idb

自1107之後，咱們銀行的核心繫統MGR已經上線兩週多了，目前仍是比較穩定，最近有點時間能夠深刻學習一下mysql 8.0的一些特性。

mysql.idb這個數據文件是在8.0纔出現，咱們來具體瞭解一下。
一、先查看一下mysql數據庫
mysql> show tables;
+---------------------------+
| Tables_in_mysql |
+---------------------------+
| columns_priv |
| component |
| db |
| default_roles |
| engine_cost |
| func |
| general_log |
| global_grants |
| gtid_executed |
| help_category |
| help_keyword |
| help_relation |
| help_topic |
| innodb_index_stats |
| innodb_table_stats |
| password_history |
| plugin |
| procs_priv |
| proxies_priv |
| role_edges |
| server_cost |
| servers |
| slave_master_info |
| slave_relay_log_info |
| slave_worker_info |
| slow_log |
| tables_priv |
| time_zone |
| time_zone_leap_second |
| time_zone_name |
| time_zone_transition |
| time_zone_transition_type |
| user |
+---------------------------+
33 rows in set (0.00 sec)

二、隨意查看一下表結構
mysql> show create table columns_priv\G;
1. row
Table: columns_priv
Create Table: CREATE TABLE columns_priv (
Host char(255) CHARACTER SET ascii COLLATE ascii_general_ci NOT NULL DEFAULT '',
Db char(64) COLLATE utf8_bin NOT NULL DEFAULT '',
User char(32) COLLATE utf8_bin NOT NULL DEFAULT '',
Table_name char(64) COLLATE utf8_bin NOT NULL DEFAULT '',
Column_name char(64) COLLATE utf8_bin NOT NULL DEFAULT '',
Timestamp timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
Column_priv set('Select','Insert','Update','References') CHARACTER SET utf8 COLLATE utf8_general_ci NOT NULL DEFAULT '',
PRIMARY KEY (Host,Db,User,Table_name,Column_name)
) /!50100 TABLESPACE mysql / ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin STATS_PERSISTENT=0 ROW_FORMAT=DYNAMIC COMMENT='Column privileges'
1 row in set (0.01 sec)

ERROR:
No query specified
關注點TABLESPACE mysql 還有ENGINE=InnoDB 只有innodb的存儲引擎纔會有.idb這樣的文件。
再看看其餘的表
mysql> show create table servers\G;
1. row
Table: servers
Create Table: CREATE TABLE servers (
Server_name char(64) NOT NULL DEFAULT '',
Host char(255) CHARACTER SET ascii COLLATE ascii_general_ci NOT NULL DEFAULT '',
Db char(64) NOT NULL DEFAULT '',
Username char(64) NOT NULL DEFAULT '',
Password char(64) NOT NULL DEFAULT '',
Port int NOT NULL DEFAULT '0',
Socket char(64) NOT NULL DEFAULT '',
Wrapper char(64) NOT NULL DEFAULT '',
Owner char(64) NOT NULL DEFAULT '',
PRIMARY KEY (Server_name)
) /!50100 TABLESPACE mysql / ENGINE=InnoDB DEFAULT CHARSET=utf8 STATS_PERSISTENT=0 ROW_FORMAT=DYNAMIC COMMENT='MySQL Foreign Servers table'
1 row in set (0.00 sec)

ERROR:
No query specifie

其餘的表也是使用的一樣的mysql表空間，並且是innodb存儲引擎。是否是說明mysql.idb這個文件是一個公共的表空間，8.0版本已經把mysql數據庫的幾乎全部的表都放在mysql這個公共表空間了。

咱們再參看一個日誌表
mysql> show create table slow_log\G;
1. row
Table: slow_log
Create Table: CREATE TABLE slow_log (
start_time timestamp(6) NOT NULL DEFAULT CURRENT_TIMESTAMP(6) ON UPDATE CURRENT_TIMESTAMP(6),
user_host mediumtext NOT NULL,
query_time time(6) NOT NULL,
lock_time time(6) NOT NULL,
rows_sent int NOT NULL,
rows_examined int NOT NULL,
db varchar(512) NOT NULL,
last_insert_id int NOT NULL,
insert_id int NOT NULL,
server_id int unsigned NOT NULL,
sql_text mediumblob NOT NULL,
thread_id bigint unsigned NOT NULL
) ENGINE=CSV DEFAULT CHARSET=utf8 COMMENT='Slow log'
1 row in set (0.00 sec)

CSV存儲引擎天然是不能把數據放在mysql.idb中，那應該是單獨存放，咱們猜想應該還會有一個mysql數據庫（一個目錄），到datadir下查看

ls -l

total 4255780
-rw-r----- 1 mysql mysql 56 Oct 12 11:39 auto.cnf
-rw-r----- 1 mysql mysql 0 Oct 12 11:42 GCS_DEBUG_TRACE
drwxr-x--- 3 mysql mysql 22 Nov 7 03:45 #ib_archive
-rw-r----- 1 mysql mysql 4926 Oct 12 13:51 ib_buffer_pool
-rw-r----- 1 mysql mysql 1073741824 Nov 26 10:34 ibdata1
-rw-r----- 1 mysql mysql 1073741824 Nov 26 10:34 ib_logfile0
-rw-r----- 1 mysql mysql 1073741824 Oct 12 11:39 ib_logfile1
-rw-r----- 1 mysql mysql 1073741824 Oct 12 11:39 ib_logfile2
-rw-r----- 1 mysql mysql 12582912 Oct 12 13:52 ibtmp1
drwxr-x--- 2 mysql mysql 187 Oct 12 13:52 #innodb_temp
drwxr-x--- 2 mysql mysql 143 Oct 12 11:39 mysql
-rw-r----- 1 mysql mysql 25165824 Nov 25 17:37 mysql.ibd
drwxr-x--- 2 mysql mysql 8192 Oct 12 13:52 performance_schema
-rw------- 1 mysql mysql 1676 Oct 12 11:39 private_key.pem
-rw-r--r-- 1 mysql mysql 452 Oct 12 11:39 public_key.pem
drwxr-x--- 2 mysql mysql 28 Oct 12 11:39 sys
-rw-r----- 1 mysql mysql 12582912 Nov 25 17:51 undo_001
-rw-r----- 1 mysql mysql 12582912 Nov 25 17:51 undo_002

cd 到mysql目錄下查看

ls -l

total 28-rw-r----- 1 mysql mysql 5594 Oct 12 11:39 general_log_201.sdi-rw-r----- 1 mysql mysql 35 Oct 12 11:39 general_log.CSM-rw-r----- 1 mysql mysql 0 Oct 12 11:39 general_log.CSV-rw-r----- 1 mysql mysql 11803 Oct 12 11:39 slow_log_202.sdi-rw-r----- 1 mysql mysql 35 Oct 12 11:39 slow_log.CSM-rw-r----- 1 mysql mysql 0 Oct 12 11:39 slow_log.CSV發現果真有兩個日誌表使用了CSV存儲引擎，這個也不難理解，存儲日誌或者數據交換數據量比較大更一些，總之經過以上咱們對mysql數據庫的結構有了進一步的認識和了解。