Glossary¶
.ARM file¶
Contains the metadata for each Archive Storage Engine table.
.ARZ file¶
Contains the data for each Archive Storage Engine table.
.CSM¶
Each table with the CSV Storage Engine has .CSM file which contains the metadata of it.
.CSV¶
Each table with the CSV Storage engine has .CSV file which contains the data of it (which is a standard Comma Separated Value file).
.exp¶
Files with the .exp extension are created by Percona XtraBackup per each InnoDB tablespace when the --export option is used in the prepare phase. See restoring individual tables.
.frm¶
For each table, the server will create a file with the .frm extension containing the table definition (for all storage engines).
.ibd¶
On a multiple tablespace setup (innodb_file_per_table enabled), MySQL will store each newly created table in a file with a .ibd extension.
.MRG¶
Each table using the MERGE storage engine, besides of a .frm file, will have .MRG file containing the names of the MyISAM tables associated with it.
.MYD¶
Each MyISAM table has .MYD (MYData) file which contains the data on it.
.MYI¶
Each MyISAM table has .MYI (MYIndex) file which contains the table’s indexes.
.opt¶
MySQL stores options of a database (like charset) in a file with a .opt extension in the database directory.
.par¶
Each partitioned table has .par file which contains metadata about the partitions.
.TRG¶
File containing the triggers associated with a table, for example :file:mytable.TRG With the .TRN file, they represent all the Trigger definitions.
.TRN¶
File containing the names of the triggers that are associated with a table, for example :file:mytable.TRN. With the .TRG file, they represent all the trigger definitions.
backup¶
The process of copying data or tables to be stored in a different location.
compression¶
The method that produces backups in a reduced size.
configuration file¶
The file that contains the server startup options.
crash¶
An unexpected shutdown that does not allow the normal server shutdown cleanup activities.
crash recovery¶
The actions that occur when MySQL is restarted after a crash.
data dictionary¶
The metadata for the tables, indexes, and table columns stored in the InnoDB system tablespace.
datadir¶
The directory in which the database server stores its data files. Most Linux distribution use /var/lib/mysql by default.
full backup¶
A backup that contains the complete source data from an instance.
ibdata¶
Default prefix for tablespace files, for example, ibdata1 is a 10MB
auto-extensible file that MySQL creates for the shared tablespace by
default.
incremental backup¶
A backup stores data from a specific point in time.
InnoDB¶
Storage engine which provides ACID-compliant transactions and foreign key support, among others improvements over MyISAM. It is the default engine for MySQL as of the 8.0 series.
innodb_buffer_pool_size¶
The size in bytes of the memory buffer to cache data and indexes of InnoDB’s tables. This aims to reduce disk access to provide better performance. By default:
[mysqld] innodb_buffer_pool_size=8MB
innodb_data_home_dir¶
The directory (relative to datadir) where the database server stores the files in a shared tablespace setup. This option does not affect the location of innodb_file_per_table. For example:
[mysqld] innodb_data_home_dir = ./
innodb_data_file_path¶
Specifies the names, sizes and location of shared tablespace files:
[mysqld] innodb_data_file_path=ibdata1:50M;ibdata2:50M:autoextend
innodb_file_per_table¶
By default, InnoDB creates tables and indexes in a file-per-tablespace. If the innodb_file_per_table variable is disabled, you can enable the variable in your configuration file:
[mysqld] innodb_file_per_table
or start the server with --innodb_file_per_table.
innodb_log_group_home_dir¶
Specifies the location of the InnoDB log files:
[mysqld] innodb_log_group_home=/var/lib/mysql
logical backup¶
A backup which contains a set of SQL statements. The statements can be used to recreate the databases.
LSN¶
Each InnoDB page (usually 16kb in size) contains a log sequence number, or LSN. The LSN is the system version number for the entire database. Each page’s LSN shows how recently it was changed.
my.cnf¶
The database server’s main configuration file. Most
Linux distributions place it as /etc/mysql/my.cnf or
/etc/my.cnf, but the location and name depends on the particular
installation. Note that this is not the only way of configuring the
server, some systems does not have one and rely on the command
options to start the server and its default values.
MyISAM¶
Previous default storage engine for MySQL for versions prior to 5.5. It doesn’t fully support transactions but in some scenarios may be faster than InnoDB. Each table is stored on disk in 3 files: .frm, .MYD, .MYI.
physical backup¶
A backup that copies the data files.
point in time recovery¶
This method allows data to be restored to the state it was in any selected point of time.
prepared backup¶
A consistent set of backup data that is ready to be restored.
restore¶
Copies the database backups taken using the backup command to the original location or a different location. A restore returns data that has been either lost, corrupted, or stolen to the original condition at a specific point in time.
xbcrypt¶
To support encryption and decryption of the backups, a new tool xbcrypt was introduced to Percona XtraBackup. This utility has been modeled after the xbstream binary to perform encryption and decryption outside of Percona XtraBackup.
xbstream¶
To support simultaneous compression and streaming, Percona XtraBackup uses the xbstream format. For more information, see --stream
XtraDB¶
Percona XtraDB is an enhanced version of the InnoDB storage engine, designed to better scale on modern hardware. Percona XtraDB includes a variety of other features useful in high performance environments. It is fully backwards compatible, and so can be used as a drop-in replacement for standard InnoDB. More information here.