InnoDB存储引擎中的表空间详解

#1.DATA STORAGE
datadir=/var/lib/mysql 
#2.InnoDB Configuration 
innodb_file_per_table=1
#3.InnoDB Memory 
innodb_buffer_pool_size = 2000M
#4.System Tablespace configuration
innodb_data_file_path= ibdata1:512M;ibdata2:512M:autoextend
#5.Redo log and buffer configuration
innodb-log-files-in-group=3
innodb_log_file_size=100M
innodb_log_buffer_size=30M
#5.InnoDB file formate 
innodb_file_format = Barracuda
#6.UNDO Tablespace Configuration 
innodb_undo_directory = /var/lib/mysql/ 
innodb_undo_tablespaces = 3 
innodb_undo_logs = 128 
innodb_undo_log_truncate = ON 
innodb_rollback_segments = 128
#7.Temp Tablespace Configuration 
tmpdir = /var/lib/mysql/ 
innodb_temp_data_file_path = ibtmp1:20M:autoextend 
#8.tablespace 数据加密插件，在Enterprise版本中提供 #Keyring configuration 
early-plugin-load=keyring_file.so 
keyring_file_data=/var/lib/mysql-keyring/keyring

# innochecksum --page-type-summary ibdata1 
File::ibdata1
================PAGE TYPE SUMMARY==============
#PAGE_COUNT     PAGE_TYPE
===============================================
  349391        Index page                        5.25%
 6076813        Undo log page                    91.29%
   18349        Inode page                        0.28%
  174659        Insert buffer free list page      2.62%
   36639        Freshly allocated page            0.55%
     405        Insert buffer bitmap              0.01%
      98        System page
       1        Transaction system page
       1        File Space Header
     404        Extent descriptor page            0.01%
       0        BLOB page
       8        Compressed BLOB page
       0        Other type of page
-------------------------------------------------------
 6656768        Pages total                     100.00%
===============================================
Additional information:
Undo page type: 3428 insert, 6073385 update, 0 other
Undo page state: 1 active, 67 cached, 249 to_free, 1581634 to_purge, 0 prepared, 4494862 other

innodb_undo_tablespace : Number of undo tablespaces, default 0 , max 95 
innodb_undo_directory : Location for undo tablespace,default is data_dir with 10MB initial size.
innodb_undo_logs : Number of undo logs in a single undo tablespace, default and max value is ‘128' [ Deprecated in 5.7.19 , innodb_rollback_segments variable will control this]    
innodb_undo_log_truncate: truncate undo tablespace, Default OFF