CkptRate

The CkptRate connection attribute controls the maximum rate at which data should be written to disk during a checkpoint operation.

This can be useful when the writing of checkpoints to disk interferes with other applications.

All background checkpoints and by checkpoints initiated by the ttCkpt and ttCkptBlocking built-in procedures use the rate specified by this connection attribute. Foreground checkpoints (checkpoints taken during first connect and last disconnect) do not use this rate. The rate is specified in MB per second.

A value of 0 disables rate limitation. This is the default. The value can also be specified using the ttCkptConfig built-in procedure. The value set by the ttCkptConfig built-in procedure replaces the value set by this attribute.

The value of this attribute is "sticky" as it persists across database loads and unloads unless it is explicitly changed. The default value is only used during database creation. Subsequent first connections default to using the existing value stored in the database. If left unspecified (or empty in the Windows ODBC Data Source Administrator), TimesTen uses the stored setting. To turn the attribute off, you must explicitly specify a value of 0. For existing databases that are migrated to this release, the value is initialized to 0. To use the current or default value, the attribute value should be left unspecified.

For more details about the benefits of and issues when using CkptRate, see Setting the Checkpoint Rate in Oracle TimesTen In-Memory Database Operations Guide.

Required Privilege

Only the instance administrator can change the value of this attribute.

Usage in TimesTen Scaleout and TimesTen Classic

This attribute is supported in both TimesTen Classic and TimesTen Scaleout.

Setting

Set CkptRate as follows:

Where to set the attribute	How the attribute is represented	Setting
C or Java programs or UNIX and Linux systems odbc.ini file in TimesTen Classic or in the database definition (.dbdef) file in TimesTen Scaleout	CkptRate	Specify the maximum rate in MB per second at which a checkpoint should be written to disk. A value of 0 indicates that the rate should not be limited. This is the default. If you do not specify this attribute, TimesTen uses the default value (0) for database creation. TimesTen uses the stored value for existing databases. If the attribute is specified, but you do not supply a value, the value of 0 is used. Specifying a value of -1 is equivalent to omitting this attribute. If you specify a value of -1, the default value (0) is used for database creation, otherwise the stored value is used.
Windows ODBC Data Source Administrator	Not applicable