9. OpenLink ODBC Driver for PostgreSQL (Express Edition)

9.2. OpenLink ODBC Driver for PostgreSQL (Express Edition) for Windows

9.2.1. Installation

The OpenLink ODBCDriver for PostgreSQL(Express Edition) is distributed as a Windows MSI installer. Simply double click on the installer 'ntl6epgr.msi' to commence the installation:

Figure: 9.2.1.1.

Installer Welcome Dialog for the OpenLink ODBCDriver for PostgreSQL(Express Edition):

Figure: 9.2.1.1.

Please read the software license agreement and accept before continuing your installation:

Figure: 9.2.1.1.

Before installation you will be prompted for a license file. If a license file already exists on the machine, then select the 'use exisiting file' option. A trial (try) or full (buy) license can be obtained by selecting the 'try and buy' option, which loads OpenLink's online try and buy web page:

Figure: 9.2.1.1.

To obtain the trial license, you must be a registered user on the OpenLinkWeb site and login with your username (e-mail address) and password. Click on the 'Shop' link to visit OpenLink's online shop cart to purchase a full license, if required:

Click on the 'download license' button to immediately obtain the license file and save it to your desktop. Alternatively, an auto-generated e-mail will be sent to your registered e-mail address. This email will contain a link to your OpenLinkData Space ( ODS). The OpenLinkData Space ( ODS) contains copies of all trial and full license files in a Briefcase for download at a later date.

Figure: 9.2.1.1.

Select the license file to be used for the installation:

Figure: 9.2.1.1.

Choose to perform a custom, typical or complete installation of the driver:

Figure: 9.2.1.1.

Select the features to be installed:

Figure: 9.2.1.1.

Click the install button to begin the installation of components:

Figure: 9.2.1.1.

Installation in progress:

Figure: 9.2.1.1.

The Software installation is complete and ready for use:

Figure: 9.2.1.1.

9.2.2. Configuration

To configure an ODBCDSN, run the ODBCAdministrator located in the Administrative Tools section of the Control Panel:

Figure: 9.2.2.1.

Click on the Drivers tab to confirm the OpenLink PostgreSQL ODBCDriver [Express Edition][6.0] has been successfully installed:

Figure: 9.2.2.1.

From either the User or System DSN tabs, click on the Add button and select the OpenLink PostgreSQL ODBCDriver [Express Edition][6.0] from the list :

Figure: 9.2.2.1.

In the Data Source tab, select a suitable DSN name and optional description for the Data Source to be created:

Figure: 9.2.2.1.

The Connection tab requests the minimum parameters required to make a connection to the target database:

Figure: 9.2.2.1.

• Host: This is the fully qualified hostname or IP address of the machine hosting the DBMS you wish to access, e.g., dbms-server.example.com, or 192.168.155.123. Any hostname which will be resolved by your local DNS is acceptable.

• Port: This is the port on which PostgreSQL is listening

• Database: This is the name of the PostgreSQL database to which you want to connect

• Login ID: This is a valid user name for the PostgreSQL database

• Password: This is a valid password for the PostgreSQL database

Click next to verify that all settings are correct or uncheck the check box to delay testing to a later stage.

The advanced button displays additional, optional parameters that can be configured:

Figure: 9.2.2.1.

As indicated above, the parameters on the options and preferences tabs are not required for a basic connection.

Figure: 9.2.2.1.

• Drop Catalog name from DatabaseMetaData calls - Enable this option to have the catalog name not appear for tables, views, and procedures when requesting database meta-data.

• Drop Schema name from DatabaseMetaData calls - Enable this option to have the schema-name not appear for tables, views, and procedures when requesting database meta-data.

• Return an empty ResultSet for SQLStatistics - Check this box to have SQLStatistics() return an empty resultset. Use this if the underlying database does not support retrieving statistics about a table, e.g., what indexes there are on it.

• Disable support of quoted identifier - If it is set, the call SQLGetInfo for 'SQL_IDENTIFIER_QUOTE_CHAR' will return the space (" "). It can be used if the DBMS does not support quoted SQL, e.g., select * from "account."

• Disable support of search pattern escape - If it is set, the call SQLGetInfo for 'SQL_LIKE_ESCAPE_CLAUSE' will return the space (" "). It can be used if the DBMS does not support SQL escape patterns.

• Patch of NULL size of SQL_CHAR - If set, this option overrides the size of SQL_CHAR column type returned by the database with the value set in the text box (in bytes). With the default value of 0, the driver uses the size returned by the database.

Figure: 9.2.2.1.

• Disable Interactive Login - Suppress the ODBC "Username" and "Password" login dialog box when interacting with your ODBC DSN from within an ODBC compliant application.

• Row Buffer Size - This attribute specifies the number of records to be transported over the network in a single network hop. Values can range from 1 to 99.

• Max rows override - Allows you to define a limit on the maximum number of rows to be returned from a query. The default value of 0 means no limit.

• Initial SQL - Lets you specify a file containing SQL statements that will be automatically run against the database upon connection.

• Dynamic Cursor Sensitivity - Enables or disables the row version cache used with dynamic cursors. When dynamic cursor sensitivity is set high, the Cursor Library calculates checksums for each row in the current rowset and compares these with the checksums (if any) already stored in the row version cache for the same rows when fetched previously. If the checksums differ for a row, the row has been updated since it was last fetched, and the row status flag is set to SQL_ROW_UPDATED. The row version cache is then updated with the latest checksums for the rowset. From the user's point of view, the only visible difference between the two sensitivity settings is that a row status flag can never be set to SQL_ROW_UPDATED, when the cursor sensitivity is low. (The row status is instead displayed as SQL_ROW_SUCCESS.) In all other respects, performance aside, the two settings are the same - deleted rows do not appear in the rowset, updates to the row since the row was last fetched are reflected in the row data, and inserted rows appear in the rowset if their keys fall within the span of the rowset. If your application does not need to detect the row status SQL_ROW_UPDATED, you should leave the 'High Cursor Sensitivity' checkbox unchecked, as performance is improved. The calculation and comparison of checksums for each row fetched carries an overhead. If this option is enabled, the table oplrvc must have been created beforehand using the appropriate OpenLink script for the target database.

• Enable logging to the log file: - Specifies the full path to a text file. If the associated checkbox is checked, and a file is passed, the driver will log auto-generate a clientside ODBC trace.

Figure: 9.2.2.1.

• Disable AutoCommit - Change the default commit behaviour of the OpenLink Driver. The default mode is AutoCommit (box unchecked).

• Disable Rowset Size Limit - Disable the limitation enforced by the cursor library. The limitation is enforced by default to prevent the Driver claiming all available memory in the event that a resultset generated from an erroneous query is very large. The limit is normally never reached.

• Multiple Active Statements Emulation - Enables use of Multiple Active statements in an ODBC application even if the underlying database does not allow this, as it is emulated in the driver.

• SQL_DBMS Name - Manually override the SQLGetInfo(SQL_DBMS_NAME) response returned by the driver. This is required for products like Microsoft InfoPath for which the return value must be "SQL Server".

Click on the Test Data Sourcebutton to verify that a successful connection can be made to the database.

Figure: 9.2.2.1.