Data Store Attributes
Data store attributes define the database's connection name, character set, and other essential specifications. These attributes can be assigned values only during database creation by the instance administrator.
Data Source Name
The data source name (DSN) uniquely identifies the attributes to a connection. It serves two purposes:
-
As a unique identifier to the ODBC driver manager (if one is present), allowing it to associate a Data Store Name with a specific ODBC driver.
-
As one of potentially many name aliases to a single physical database where the name alias has unique attributes associated with it.
The database attributes can apply to either the data source name (connection to a database) or the Data Store Path Name (database).
On Windows, the data source name and all configuration information associated with the data source (including the database path name) are stored in the system registry. The ODBC driver manager and TimesTen use this information.
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 Data Source Name
as follows:
Where to set the attribute | How the attribute is represented | Setting |
---|---|---|
C or Java programs or UNIX and Linux systems |
|
A name that describes the DSN. |
Windows ODBC Data Source Administrator |
Not applicable |
DataStore
The database path name uniquely identifies the physical database. It is the fully qualified directory path name of the database and the file name prefix, for example: /disk1/databases/database1
. This name is not a file name. The actual database file names have suffixes, such as .ds0
and .log0
, for example /disk1/databases/database1.ds0
and /disk1/databases/database1.log0
.
Note:
You are required to specify the database path and name at database creation time. It cannot be altered after the database has been created.
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 DataStore
as follows:
Where to set the attribute | How the attribute is represented | Setting |
---|---|---|
C or Java programs or UNIX and Linux systems |
|
Full path to the physical database that the data source name references. |
Windows ODBC Data Source Administrator |
Not applicable |
DatabaseCharacterSet
The database character set determines the character set in which data is stored.
Note:
You are required to specify the database character set at database creation time only. It cannot be altered after the database has been created. If you do not specify a value for this attribute when creating a database, TimesTen returns error message 12701.
Generally, your database character set should be chosen based on the data requirements. For example: Do you have data in Unicode or is your data in Japanese on UNIX and Linux systems (EUC
) or Windows (SJIS
)?
You should choose a connection character set that matches your terminal settings or data source. See ConnectionCharacterSet.
When the database and connection character sets differ, TimesTen performs the data conversion internally based on the connection character set. If the connection and database character sets are the same, TimesTen does not need to convert or interpret the data set. Best performance occurs when connection and database character sets match, since no conversion is required.
To use this attribute you must specify a supported character set. For a list of supported character set names, see Supported Character Sets below.
There are several things to consider when choosing a character set for your database. For a discussion about these considerations, see Choosing a Database Character Set 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 DatabaseCharacterSet
name as follows:
Where to set the attribute | How the attribute is represented | Setting |
---|---|---|
C or Java programs or UNIX and Linux systems |
|
Specify the preferred character set. |
Windows ODBC Data Source Administrator |
Not applicable |
Supported Character Sets
The following tables describe the character sets supported in TimesTen.
Asian Character Sets
Name | Description |
---|---|
|
|
|
The same as |
|
|
|
The same as |
|
|
|
Microsoft Windows Code Page 949 Korean |
|
Thai Industrial Standard 620-2533 - ASCII 8-bit |
|
Microsoft Windows Code Page 1258 8-bit Vietnamese |
|
|
|
|
|
|
|
|
|
Microsoft Windows Code Page 950 with Hong Kong Supplementary Character Set |
|
Microsoft Windows Code Page 950 Traditional Chinese |
European Character Sets
Name | Description |
---|---|
|
Latvian Standard |
|
ISO 8859-13 Baltic |
|
Microsoft Windows Code Page 1257 8-bit Baltic |
|
IBM-PC Code Page 775 8-bit Baltic |
|
ISO 8859-13 Celtic |
|
ISO 8859-5 Latin/Cyrillic |
|
RELCOM Internet Standard 8-bit Latin/Cyrillic |
|
KOI8 Ukrainian Cyrillic |
|
Microsoft Windows Code Page 1251 8-bit Latin/Cyrillic |
|
ISO 8859-2 East European |
|
ISO 8859-7 Latin/Greek |
|
Microsoft Windows Code Page 923 8-bit Estonian |
|
Microsoft Windows Code Page 1250 8-bit East European |
|
Microsoft Windows Code Page 1253 8-bit Latin/Greek |
|
IBM-PC Code Page 737 8-bit Greek/Latin |
|
IBM-PC Code Page 852 8-bit East European |
|
Microsoft Windows Code Page 921 8-bit Lithuanian |
|
ISO 8859-10 North European |
|
ISO 8859-4 North and North-East European |
|
IBM-PC Code Page 866 8-bit Latin/Cyrillic |
|
ISO 8859-3 South European |
|
ASCII 7-bit American |
|
IBM-PC Code Page 437 8-bit American |
|
ISO 8859-1 West European |
|
ISO 8859-15 West European |
|
Microsoft Windows Code Page 1252 8-bit West European |
|
IBM-PC Code Page 850 8-bit West European |
|
IBM-PC Code Page 858 8-bit West European |
Middle Eastern Character Sets
Name | Description |
---|---|
|
Arabic MS-DOS 720 Server 8-bit Latin/Arabic |
|
ASMO Extended 708 8-bit Latin/Arabic |
|
ISO 8859-6 Latin/Arabic |
|
Microsoft Windows Code Page 1256 8-Bit Latin/Arabic |
|
ISO 8859-9 Latin Azerbaijani |
|
ISO 8859-8 Latin/Hebrew |
|
Microsoft Windows Code Page 1255 8-bit Latin/Hebrew |
|
Microsoft Windows Code Page 1254 8-bit Turkish |
|
IBM-PC Code Page 857 8-bit Turkish |
|
ISO 8859-9 West European & Turkish |
Universal Character Sets
Name | Description |
---|---|
|
Unicode 4.0 UTF-16 Universal character set. This is the implicit TimesTen national character set. This character set cannot be specified as a value to the DatabaseCharacterSet or ConnectionCharacterSet attributes. |
|
Unicode 4.0 UTF-8 Universal character set |
|
Unicode 3.0 UTF-8 Universal character set, CESU-8 compliant |
Description
Optionally, set this attribute to help you identify the Data Source Name (DSN) and its attributes.
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 Description
as follows:
Where to set the attribute | How the attribute is represented | Setting |
---|---|---|
C or Java programs or UNIX and Linux systems |
|
Text description of the Data Source Name. This attribute is optional. |
Windows ODBC Data Source Administrator |
Not applicable |
Driver
The Driver
attribute specifies the name of the TimesTen ODBC Driver.
For example, on Windows systems the value can be TimesTen Client 22.1
.
On UNIX and Linux systems, the value of the Driver
attribute is the path name of the TimesTen ODBC Driver shared library file, timesten_home
/install/lib/libtten.so
.
For more information, see Creating a DSN on Linux and UNIX for TimesTen Classic in Oracle TimesTen In-Memory Database Operations Guide.
For general usage scenarios, refer to standard ODBC reference documentation, such as:
https://docs.microsoft.com/en-us/sql/odbc/reference/syntax/odbc-api-reference
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 Driver
as follows:
Where to set the attribute | How the attribute is represented | Setting |
---|---|---|
C or Java programs or UNIX and Linux systems |
|
Specifies the path name for the TimesTen ODBC Driver shared library file, if using a Driver Manager. |
Windows ODBC Data Source Administrator |
Select a driver from the Create New Data Source dialog. |
Specifies the client driver for TimesTen and the release. |
Durability
For TimesTen Scaleout, the setting of this attribute determines the durability of "prepare-to-commit" and commit records.
If K-safety is set to 2 or greater, the default value is 0
.
If K-safety is set to 1, the default value is 1
.
Durability=0
is not supported with K-safety set to 1.
For details about setting up K-safety, see Creating a Grid in the Oracle TimesTen In-Memory Database Scaleout User's Guide.
Required Privilege
No privilege is required to change the value of this attribute.
Usage in TimesTen Scaleout and TimesTen Classic
This attribute is not supported in TimesTen Classic.
This attribute is supported in TimesTen Scaleout.
Setting
Set Durability
as follows:
Where to set the attribute | How the attribute is represented | Setting |
---|---|---|
C or Java programs or UNIX and Linux systems database definition ( |
|
|
Windows ODBC Data Source Administrator |
N/A |
CreateEpochAtCommit
.
GridLogRecoveryThreshold
The GridLogRecoveryThreshold
attribute determines the number of log files that are prevented from purging before declaring another replica set element is declared unrecoverable.
Default value is 0, which means TimesTen saves all the log files. When the value is set to some thing non-zero, log files will keep getting accumulated until the threshold value is reached. Once the threshold is reached, the replica set element for which the log files are being saved is declared as unrecoverable.
Required Privilege
Only the instance administrator can change the value of this attribute.
Usage in TimesTen Scaleout and TimesTen Classic
This attribute is supported only in TimesTen Scaleout.
Setting
Set GridLogRecoveryThreshold
as follows:
Where to set the attribute | How the attribute is represented | Setting |
---|---|---|
C or Java programs or UNIX and Linux systems |
|
A positive integer that specifies the number of log files to preserve before declaring a replica set element is unrecoverable. The default is 0, meaning all files are saved. |
Windows ODBC Data Source Administrator |
Not applicable |
LogDir
The LogDir
attribute specifies the fully qualified directory path name where database logs reside. Specifying this attribute enables you to place the transaction log files on a different I/O path from the database checkpoint files. Placing the transaction log files and checkpoint files on different disks can improve system performance.
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 LogDir
as follows:
Where to set the attribute | How the attribute is represented | Setting |
---|---|---|
C or Java programs or UNIX and Linux systems |
|
Specifies the directory where transaction log files reside. |
Windows ODBC Data Source Administrator |
Not applicable |
Preallocate
The Preallocate
attribute determines whether TimesTen preallocates disk space for the database checkpoint files when the database is created. Setting this attribute ensures that there is sufficient space for the database when the database is saved to the file system.
TimesTen respects the setting for the Preallocate
attribute for all operations that create a new checkpoint file, such as database creation, ttRepAdmin -duplicate
, and ttRestore
.
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 Preallocate
as follows:
Where to set the attribute | How the attribute is represented | Setting |
---|---|---|
C or Java programs or UNIX and Linux systems |
|
|
Windows ODBC Data Source Administrator |
Not applicable |
Note:
Reallocating disk space for a large database is very time consuming.
ReplicationApplyOrdering
ReplicationApplyOrdering
enables parallel replication.
When used with the ReplicationParallelism attribute, multiple transmitters on the master send to multiple receivers on the subscriber.
-
Automatic parallel replication: Parallel replication over multiple threads that automatically enforces transactional dependencies and all changes applied in commit order. This is the default.
-
Automatic parallel replication with disabled commit dependencies: Parallel replication over multiple threads that automatically enforces transactional dependencies, but does not enforce transactions committed in the same order on the subscriber database as on the active database. You can also increase replication throughput by applying transactions to specific tracks.
For more details on configuring parallel replication, see Configuring Parallel Replication in Oracle TimesTen In-Memory Database Replication Guide.
This attribute also sets parallel propagation for AWT cache groups. By default, this attribute enables parallel propagation of updates to the Oracle database. To learn more about parallel AWT caching, see Improving AWT Throughput with Parallel Propagation to the Oracle Database in Oracle TimesTen In-Memory Database Cache 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 TimesTen Classic but not supported in TimesTen Scaleout.Setting
Set ReplicationApplyOrdering
as follows:
Where to set the attribute | How the attribute is represented | Setting |
---|---|---|
C or Java programs or UNIX and Linux systems |
|
|
Windows ODBC Data Source Administrator |
Not applicable |
Restrictions
Restrictions when using automatic parallel replication with disabled commit dependencies:
-
The replication scheme must be an active standby pair that uses asynchronous replication. Classic replication schemes are not supported.
-
The replication scheme cannot contain cache groups.
-
This is only supported for TimesTen Release 11.2.2.8 and greater for both the active and standby masters. Both the active and standby masters must have commit dependencies disabled.
-
XLA is not supported.
All data stores in the replication scheme must use the same setting.
ReplicationParallelism
This attribute specifies the number of tracks, or the number of transmitter/receiver pairs, used for automatic parallel replication.
Set ReplicationParallelism
to a number from 2 to 32. This number indicates the number of transmitter threads on the source database and the number of receiver threads on the target database. However, if you are using single-threaded replication, set ReplicationParallelism
to 1, which is the default.
The LogBufParallelism and ReplicationParallelism
connection attributes are related. LogBufParallelism
specifies the number of strands that are mapped to the threads that are specified by ReplicationParallelism
. For example, if LogBufParallelism
= 4 and ReplicationParallelism
= 4, then one strand is mapped to one thread. If LogBufParallelism
= 8 and ReplicationParallelism
= 4, then two strands are mapped to one thread.
Thus, if ReplicationParallelism
is greater than 1, the LogBufParallelism
connection attribute must be equal to or greater than the value of ReplicationParallelism
. The ReplicationParallelism
connection attribute cannot exceed the value of LogBufParallelism
. In order for the number of strands to be equally distributed across the number of threads, you may want to make LogBufParallelism
a multiple of the number of threads specified in ReplicationParallelism
.
To learn more about automatic parallel replication, see Configuring Parallel Replication in the Oracle TimesTen In-Memory Database Replication 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 TimesTen Classic but not supported in TimesTen Scaleout.Setting
Set ReplicationParallelism
as follows:
Where to set the attribute | How the attribute is represented | Setting |
---|---|---|
C or Java programs or UNIX and Linux systems |
|
|
Windows ODBC Data Source Administrator |
Not applicable |
Restrictions
When parallel replication is enabled, the Description column of the ttLogHolds
built-in procedure displays one row per track per subscriber node.