If the Overwrite attribute is set and there is an existing data store with the same data store path name as the new data store, TimesTen destroys the existing data store and creates a new empty data store, as long as the existing data store is not in use. If the Overwrite attribute is set and there is not a data store with the specified data store path name, TimesTen only creates a new data store if the AutoCreate attribute is also set (see "AutoCreate" on page 1-23). Overwrite is ignored if AutoCreate is set to 0. Applications should use caution when specifying the Overwrite =1 attribute.
Required privilege
Only the instance administrator can change the value of this attribute. If a user other than an instance administrator attempts to connect to a data store with
OVERWRITE=1, TimesTen returns an error.
Setting
Set Overwrite as follows:
Where to set the attribute
How the attribute is
represented Setting
C or Java programs or UNIX ODBC.INI file
Overwrite 0 - Does not overwrite existing data store with the same path name (default).
1 - Overwrites existing data store with the same path name.
Windows ODBC Data Source Administrator
PermSize
PermSize
Indicates the size in MB of the permanent memory region for the data store. You may increase PermSize at first connect but not decrease it. TimesTen returns a warning if you attempt to decrease the permanent memory region size. If the data store does not exist, a PermSize value of 0 or no value indicates that the default size should be used. Default size is 32 MB. For an existing data store, a value of 0 or no value indicates that the existing size should not be changed.
Once you have created a data store, you can make the permanent partition larger, but not smaller. See "Specifying the size of a data store" in Oracle TimesTen In-Memory Database Operations Guide.
The ttMigrate and ttDestroy utilities can also be used to change the Permanent Data Size, when appropriate.
Required privilege
Only the instance administrator can change the value of this attribute.
Setting
Set PermSize as follows:
Where to set the attribute
How the attribute is
represented Setting
C or Java programs or UNIX ODBC.INI file
PermSize n - Size of permanent partition of the data store, in megabytes; default is 32 MB for both 32-bit systems and 64-bit systems. Minimum size is 32 MB.
Windows ODBC Data Source Administrator
Permanent Data Size field n - Size of permanent partition of the data store, in megabytes; default is 32 MB for both 32-bit systems and 64-bit systems. Minimum size is 32 MB.
Data Store Attributes 1-41
ReceiverThreads
This attribute controls the number of threads used to apply changes on the active master data store to the standby master data store in an active standby pair replication scheme. The default is 1. You can also set this attribute on one or more read-only subscribers in an active standby pair replication scheme to increase replication throughput from the standby master data store to the subscribers.
By default, a receiver thread in the replication agent applies the changes to the standby master data store. When this attribute is set to 2, an additional thread applies the changes. Data stores must be hosted on systems that are 2-way or larger to take advantage of setting this attribute to 2.
If you set this attribute to 2 on the standby master data store, you should also set it to 2 on the active master data store to maintain increased throughput if there is a failover.
Required privilege
Only the instance administrator can change the value of this attribute.
Setting
Set ReceiverThreads as follows: Where to set the
attribute
How the attribute is
represented Setting
C or Java programs or UNIX ODBC.INI file
ReceiverThreads n - The number of threads used to apply changes from the active master data store to the standby master data store. You can also set this attribute on one or more read-only subscribers in an active standby pair replication scheme to increase replication throughput from the standby master data store to the subscribers. The possible values are 1 and 2. Default is 1. Windows ODBC
Data Source Administrator
ReceiverThreads
field
n - The number of threads used to apply changes from the active master data store to the standby master data store. You can also set this attribute on one or more read-only subscribers in an active standby pair replication scheme to increase replication throughput from the standby master data store to the subscribers. The possible values are 1 and 2. Default is 1.
RecoveryThreads
RecoveryThreads
The RecoveryThreads attribute determines the number of threads used to rebuild indexes during recovery.
If RecoveryThreads=1, during recovery, indexes that must be rebuilt are done serially. If you have enough processors available to work on index rebuilds on your computer, setting this attribute to a number greater than 1 can improve recovery performance. The performance improvement occurs only if different processors can work on different indexes. There is no parallelism in index rebuild within the same index. The value of RecoveryThreads can be any value up to the number of CPUs available on your system.
The default is 1 when the database is created. Upon subsequent connections, if the database must be recovered and RecoveryThreads is unspecified or has a value of 0, then TimesTen uses the previous setting for this attribute.
Required privilege
Only the instance administrator can change the value of this attribute.
Setting
Set RecoveryThreads as follows:
Notes
For a progress report on the recovery process, see the rebuild messages in the support log.
Set the number of threads low enough to leave sufficient resources on the server for other services/processes.
Where to set the attribute
How the attribute is
represented Setting
C or Java programs or UNIX ODBC.INI file
RecoveryThreads n - The number of threads to use when
rebuilding indexes during recovery. Default is 1 when the database is created and 0 on
subsequent connections. Windows ODBC Data Source Administrator RecoveryThreads field
n - The number of threads to use when
rebuilding indexes during recovery. Default is 1 when the database is created and 0 on
Data Store Attributes 1-43
TempSize
TempSize indicates the total amount of memory in MB allocated to the temporary region. TempSize has no pre-defined fixed default value. If left unspecified, its value is determined from PermSize as follows:
TimesTen rounds the value up to the nearest MB.
If PermSize is greater than 64MB, TempSize =14 MB + ceiling(PermSize / 8 MB). If PermSize is less than 64MB, TempSize = 6 MB + ceiling(PermSize / 4 MB). If specified, TimesTen always honors the TempSize value. Since the temporary data partition is recreated each time a data store is loaded, the TempSize attribute may be increased or decreased each time a data store is loaded. For an existing data store, a value of 0 or no value indicates that the existing size should not be changed. The minimum TempSize is 32 MB.
Required privilege
Only the instance administrator can change the value of this attribute.
Setting
Set TempSize as follows:
Where to set the attribute
How the attribute is
represented Setting
C or Java programs or UNIX ODBC.INI file
TempSize n - Size of temporary partition of the data store, in
megabytes. Minimum size is 32 MB on all platforms. Windows ODBC Data Source
Administrator
Temporary Data Size field n - Size of temporary partition of the data store, in
megabytes. Minimum size is 32 MB on all platforms.