Oracle 5.0 Reference Manual page 1263

in hardware caches, or use some other command specific to the hardware
vendor.
•
innodb_flush_method
Command-Line Format
Option-File Format
Option Sets Variable
Variable Name
Variable Scope
Dynamic Variable
If set to
fdatasync
uses
O_DSYNC, InnoDB
If is specified (available on some GNU/Linux versions, FreeBSD, and Solaris),
O_DIRECT
uses (or
O_DIRECT
the data and log files. Note that
use by default because there have been problems with it on many varieties of Unix. This
O_DSYNC
variable is relevant only for Unix. On Windows, the flush method is always
cannot be changed.
Different values of this variable can have a marked effect on
on some systems where
setting
innodb_flush_method
statements by a factor of three.
•
innodb_force_recovery
Command-Line Format
Option-File Format
Option Sets Variable
Variable Name
Variable Scope
Dynamic Variable
Startup Options and System Variables
InnoDB
--innodb_flush_method=name
innodb_flush_method
Yes,
innodb_flush_method
innodb_flush_method
Global
No
Permitted Values
Type
enumeration
(windows)
Default
async_unbuffered
(the default),
InnoDB
to open and flush the log files, and
O_SYNC
on Solaris) to open the data files, and uses
directio()
uses
InnoDB
data and log files are located on a SAN, it has been found that
InnoDB
[1243] to
--innodb_force_recovery=#
innodb_force_recovery
Yes,
innodb_force_recovery
innodb_force_recovery
Global
No
Permitted Values
Type
enumeration
Default
0
Valid
0
Values
1
2
3
4
5
1243
[1243]
uses to flush both the data and log files. If set to
fsync()
instead of fdatasync(), and it does not
fsync()
InnoDB
can degrade performance of simple
O_DIRECT
[1243]
to flush the data files.
fsync()
InnoDB
to flush both
fsync()
async_unbuffered
performance. For example,
SELECT
and