The Historian stores and retrieves data from any database using JDBC. The Historian communicates with your database using either a direct JDBC connection or an ODBC-JDBC bridge connection. Both connections require some setup before the Historian can communicate with your database.

Direct JDBC Connection
Before the Historian can communicate with your database using a direct JDBC connection, you must have a JDBC driver for your database. JDBC drivers are available from most database vendors. Locate the JDBC driver on your machine and define an environment variable named RTV_USERPATH that includes a path to the driver class or .jar file that contains the driver class. NOTE: You may define RTV_USERPATH to include paths to multiple driver classes. The RTV_USERPATH variable is included in the classpath for Enterprise RTView and the Historian.

When you setup the database in the Historian, you must know the fully qualified class name for the driver class and the database URL required to connect to your database. The database URL typically contains protocol and sub-protocol strings for your database, as well as the path to the database and a list of properties. If you do not know the syntax for your database URL, consult the documentation for your JDBC driver.

ODBC-JDBC Bridge Connection
Before the Historian can communicate with your database using an ODBC-JDBC bridge, you must have an ODBC driver for your database. Most databases that run on Microsoft Windows come standard with an ODBC driver. You must also register your database with ODBC before accessing it from Enterprise RTView. The name specified for the ODBC data source name during the ODBC driver setup must be RTVHISTORY.

After you have setup your database, run the Historian and configure the connection in the Database Options section. Once you have configured the connection, the Historian will be able to connect to your database.  NOTE: If you are using a direct JDBC connection or a password protected ODBC-JDBC bridge connection to communicate with the history database, you will need to configure the history database in the Display Builder before viewing your history data. To configure the history database in the Display Builder, go to the Application Options SQL tab and add a database named RTVHISTORY with the same configuration options used in the Historian. See the SQL Application Options page in the Data Sources section of this documentation for more information.

History Tables
The Historian archives data to two history tables in your database: one for numeric data, the other for string (i.e., textual) data. By default the numeric table is HISTORY and the string table is HISTORY_S. You can specify your own history table name (e.g., MY_TABLE) on the command line for the Historian. The table name you specify will be used for the numeric table. An _S will be appended to the table name for the string table (e.g., MY_TABLE_S). NOTE: Table names cannot contain spaces. If you do specify your own history table name, you will also need to indicate this name on the command line for the Display Builder and Display Viewer Application or in your Display Viewer Applet parameters.

If these history tables don't already exist in your database, they will be created for you the first time you run the Historian. If you do not want the Historian to create these tables, create your own history tables manually before running the Historian using the fields described in the table below.

Tabular Data
To store tabular data, it is recommended that you create a separate history table in the database. Specify the table name you create in Object Properties under historyTableName. This table must include a column for each column in your tabular data element along with two text columns placed at the end to store time stamp values. If you select the historyTableRowNameFlag check box in Object Properties, then you must include another text column placed at the beginning of the table to store row name values. If you choose not to create a table, then data from your tabular element will be stored in HISTORY or HISTORY_S and, in the case of tabular data with multiple columns, row integrity will be lost. NOTE: User defined tables cannot be used with the valueHistoryFlag to load initial history data on graph traces. You can view this data in your display using an SQL data attachment. For an example of storing tabular data, see the Archiving and Viewing Historical Data example.

The numeric table (HISTORY or the table name you specified) should contain numeric information. The following fields are required:
 

Field Name	Field Type	Field Description	Recommended Field Length (if applicable)
VAR_NAME	Text	The data attachment used to store this record.	80-160
TIME_STAMP	Text	The time this record was stored. This value is rounded to the closest second.	30
TIME_STAMP_LS	Text	A string value of the time this record was stored. This value contains the time including milliseconds.	14
VAR_VALUE	double	The value for this field. This value is a number.

The string table (HISTORY_S or the table name you specified) should contain text information. The following fields are required:
 

Field Name	Field Type	Field Description	Recommended Field Length (if applicable)
VAR_NAME	Text	The data attachment used to store this record.	80-160
TIME_STAMP	Text	The time this record was stored. This value is rounded to the closest second.	30
TIME_STAMP_LS	Text	A string value of the time this record was stored. This value contains the time including milliseconds.	14
VAR_SVALUE	Text	The value for this field. This value is a string.	40

Register Your Database with ODBC

Windows:

1.    From the Windows Control Panel, double-click on the ODBC Data Sources icon. If this icon is not listed, double-click on the Administrative Tools icon and then double-click on the Data Sources (ODBC) icon. This will open the ODBC dialog.

2.    In the ODBC dialog, click Add. In the Create New Data Source window, select the driver for which you want to setup a data source. Click Finish to bring up the Setup dialog.

3.    Enter the following Data Source Name: RTVHISTORY

4.    Click the Select button and choose the database to which you would like the Historian to store data.

5.    Click OK in the Select Database, Setup, and ODBC dialogs.

UNIX:

UNIX systems do not come standard with an ODBC driver. Contact your system administrator for information on how to install and setup an ODBC driver for your database.