Oracle 5.0, Reference Manual

Page: 1260 / 3232

InnoDB
Startup Options and System Variables
1240
•
innodb_data_file_path
Command-Line Format
--innodb_data_file_path=name
Option-File Format
innodb_data_file_path
Variable Name
innodb_data_file_path
Variable Scope Global
Dynamic Variable No
The paths to individual data files and their sizes. The full directory path to each data file is formed
by concatenating
innodb_data_home_dir
[1240] to each path specified here. The file sizes are
specified in KB, MB, or GB (1024MB) by appending
K
,
M
, or
G
to the size value. The sum of the sizes
of the files must be at least 10MB. If you do not specify
innodb_data_file_path
[1240] , the
default behavior is to create a single 10MB auto-extending data file named
ibdata1
. The size limit
of individual files is determined by your operating system. You can set the file size to more than
4GB on those operating systems that support big files. You can also use raw disk partitions as data
files. For detailed information on configuring
InnoDB
tablespace files, see Section 14.2.1, “
InnoDB
Configuration” .
•
innodb_data_home_dir
Command-Line Format
--innodb_data_home_dir=path
Option-File Format
innodb_data_home_dir
Option Sets Variable Yes,
innodb_data_home_dir
[1240]
Variable Name
innodb_data_home_dir
Variable Scope Global
Dynamic Variable No
Permitted Values
Type
file name
The common part of the directory path for all
InnoDB
data files in the shared tablespace. This setting
does not affect the location of per-file tablespaces when
innodb_file_per_table
[1241] is
enabled. The default value is the MySQL data directory. If you specify the value as an empty string,
you can use absolute file paths in
innodb_data_file_path
[1240] .
•
innodb_doublewrite
Version Introduced 5.0.3
Command-Line Format
--innodb-doublewrite
Option-File Format
innodb_doublewrite
Option Sets Variable Yes,
innodb_doublewrite
[1240]
Variable Name
innodb_doublewrite
Variable Scope Global
Dynamic Variable No
Permitted Values
Type
boolean
If this variable is enabled (the default),
InnoDB
stores all data twice, first to the doublewrite
buffer, and then to the actual data files. This variable can be turned off with
--skip-
innodb_doublewrite
for benchmarks or cases when top performance is needed rather than
concern for data integrity or possible failures. This variable was added in MySQL 5.0.3.