Chapter 5 Database Options
181
If COOPERATIVE_COMMITS is set to ON (the default), the database
server does not immediately write the COMMIT to the disk. Instead, the
application waits for up to the maximum length set by the
COOPERATIVE_COMMIT_TIMEOUT option for something else to put on
the pages before they are written to disk.
Setting COOPERATIVE_COMMITS to ON, and increasing the
COOPERATIVE_COMMIT_TIMEOUT setting, increases overall database
server throughput by cutting down the number of disk I/Os, but at the
expense of a longer turnaround time for each individual connection.
If both COOPERATIVE_COMMITS and DELAYED_COMMITS are set to
ON, and the COOPERATIVE_COMMIT_TIMEOUT interval passes
without the pages getting written, the application is resumed (as if the
commit had worked), and the remaining interval
(DELAYED_COMMIT_TIMEOUT -
COOPERATIVE_COMMIT_TIMEOUT) is used as a
DELAYED_COMMIT interval. The pages will then be written, even if they
are not full.
COOPERATIVE_COMMIT_TIMEOUT option
Governs when a COMMIT entry in the transaction log is written to disk.
Integer, in milliseconds
Can be set for an individual connection or for the PUBLIC group. Takes
effect immediately.
250
This option has meaning only when COOPERATIVE_COMMITS is set to
ON. The database server waits for the specified number of milliseconds for
other connections to fill a page of the log before writing to disk. The default
setting is 250 milliseconds.
DATE_FORMAT option
Sets the format for dates retrieved from the database.
String
Can be set for an individual connection or for the PUBLIC group. Takes
effect immediately.
’YYYY-MM-DD’. This corresponds to ISO date format specifications.
Function
Allowed values
Scope
Default
Description
Function
Allowed values
Scope
Default
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