Configuring Data Sources
After you install the driver, you need to configure a data source or use a connection string to connect to the database. If you want to use a data source, but need to change some of its values, you can either modify it or override its values through a connection string. See "Quick Start Connect" for an explanation of different types of data sources.
If you choose to use a connection string, you must use specific connection string attributes. See "Connecting to a Data Source Using a Connection String" and Table 5-1 for a complete description of driver connection string attributes and their values.
UNIX
On UNIX and Linux, you must set up the proper ODBC environment before configuring data sources. See "Environment Configuration" for basic setup information and "Environment Variables" for more detail about this procedure.
Data sources are stored in the system information file (by default, odbc.ini). If you have a Motif GUI environment on UNIX or Linux, you can configure and modify data sources through the DataDirect ODBC Data Source Administrator for UNIX/Linux (the UNIX ODBC Administrator) using a driver Setup dialog box, as described in the following procedure. (See "Configuration Through the UNIX ODBC Administrator" for a detailed explanation of the Administrator.)
If you do not have a GUI environment, you can configure and modify data sources directly by editing the system information file and storing default connection values there. See "Configuration Through the System Information File" for detailed information about the specific steps necessary to configure a data source.
Table 5-1 lists driver connection string attributes that must be used in the system information file. Note that only the long name of the attribute can be used in the file.
Windows
On Windows, data sources are stored in the Windows Registry. You can configure and modify data sources through the ODBC Administrator using a driver Setup dialog box, as described in the following section.
Configuration
Default connection values are specified through the options on the tabs of the Setup dialog box. Connection string attributes that override these options have the same names as the options unless noted otherwise. The connection string attribute name does not have spaces between the words. For example, the option name Application Using Threads is equivalent to the connection string attribute name ApplicationUsingThreads.
NOTE: This book shows dialog box images that are specific to Windows. If you are using the drivers in the UNIX/Linux environments, the dialog box that you see may differ slightly from the Windows version. Windows-only and UNIX-only connection options are specifically noted by icons in the Setup dialog box descriptions.
By default, edit boxes and drop-down lists on the Setup dialog box are empty unless a specific default is otherwise noted.
To configure an Informix data source:
- Start the ODBC Administrator:
- Select a tab:
- User DSN: If you are configuring an existing user data source, select the data source name and click Configure to display the driver Setup dialog box.
System DSN: If you are configuring an existing system data source, select the data source name and click Configure to display the driver Setup dialog box.- File DSN: If you are configuring an existing file data source, select the data source file and click Configure to display the driver Setup dialog box.
- On the General tab, provide the following information; then, click Apply.
- Optionally, click the Advanced tab to specify additional data source settings.
- Optionally, click the Failover tab to specify Failover data source settings.
- At any point during the configuration process, you can click Test Connect to attempt to connect to the data source using the connection options specified in the driver Setup dialog box. A logon dialog box appears (see "Connecting to a Data Source Using a Logon Dialog Box" for details). Note that the information you enter in the logon dialog box during a test connect is not saved.
- If the driver can connect, it releases the connection and displays a
Connection Establishedmessage. Click OK. - If the driver cannot connect because of an incorrect environment or connection value, it displays an appropriate error message. Click OK.
- Click OK or Cancel. If you click OK, the values you have specified become the defaults when you connect to the data source. You can change these defaults by using this procedure to reconfigure your data source. You can override these defaults by connecting to the data source using a connection string with alternate values.
If you are configuring a new user data source, click Add to display a list of installed drivers. Select the driver and click Finish to display the driver Setup dialog box.
If you are configuring a new system data source, click Add to display a list of installed drivers. Select the driver and click Finish to display the driver Setup dialog box.
If you are configuring a new file data source, click Add to display a list of installed drivers. Select the driver and click Advanced to specify attributes; otherwise, click Next to proceed. Specify a name for the data source and click Next. Verify the data source information; then, click Finish to display the driver Setup dialog box.
The General tab of the Setup dialog box appears by default.
NOTE: The General tab displays only fields that are required for creating a data source. The fields on all other tabs are optional, unless noted otherwise.
Data Source Name: Type a string that identifies this Informix data source configuration. Examples include Accounting or INFORMIX-Serv1.
Description: Type an optional long description of a data source name. For example, My Accounting Database or Informix files on Server number 1.
Host Name: Type the name of the machine on which the Informix database resides or enter an IP address.
The numeric IP address can be specified in either IPv4 or IPv6 format, or a combination of the two. See "Using IP Addresses" for details concerning these formats.
Port Number: Type the port number of the server listener.
Server Name: Type the name of the Informix server.
Database Name: Type the name of the database to which you want to connect by default.
The equivalent connection string attribute is Database.
User Name: Type your user name as specified on the Informix server.
The equivalent connection string attribute is LogonID.
On this tab, provide any of the following optional information; then, click Apply.
Cancel Detect Interval: Select a value other than 0 - None to allow long-running queries in threaded applications to be canceled if the application issues a SQLCancel. The value you select determines how often (in seconds) the driver checks whether a query has been canceled using SQLCancel. If the driver determines that SQLCancel has been issued, the query is canceled. For example, if you select 5, then for every pending query, the driver checks every five seconds to see whether the application has canceled execution of the query using SQLCancel. The default is 0, which means that queries are not canceled even if SQLCancel is issued.
This connection option can affect performance. See "Performance Considerations" for details.
IANAAppCodePage: For a list of valid values for this option, refer to "Values for the Attribute IANAAppCodePage" in the DataDirect Connect64 for ODBC and Connect64 XE for ODBC Reference. You need to specify a value for this option if your application is not Unicode-enabled and/or if your database character set is not Unicode (refer to "Internationalization, Localization, and Unicode" in the DataDirect Connect64 for ODBC and Connect64 XE for ODBC Reference for details). The value you specify must match the database character encoding and the system locale.
The Driver Manager checks for the value of IANAAppCodePage in the following order:
If no IANAAppCodePage value is found, the driver uses the default value of 4 (ISO 8859-1 Latin-1).
Application Using Threads: Select this check box to ensure that the driver works with multi-threaded applications. You can clear this check box when using the driver with single-threaded applications. Turning off this setting avoids additional processing required for ODBC thread-safety standards. By default, the check box is selected.
This connection option can affect performance. See "Performance Considerations" for details.
Trim Blank From Index Name: Select this check box to trim the leading space from a system-generated index name (the default). This option is provided to address problems with applications that cannot process a leading space in index names.
Use Delimited Identifier: Select this check box to enable the driver to set the DELIMIDENT Informix environment variable, causing the Informix server to interpret strings enclosed in double quotation marks as identifiers, not as string literals.
When this check box is not selected (the default), the Informix server interprets strings enclosed in double quotation marks as string literals, not as identifiers.
Translate: Click Translate to display the Select Translator dialog box, which lists the translators specified in the ODBC Translators section of the Registry. DataDirect provides a translator named OEM to ANSI that translates your data from the IBM PC character set to the ANSI character set.
Select a translator; then, click OK to close this dialog box and perform the translation.
On this tab, provide any of the following optional information; then, click Apply.
Load Balancing: Select this check box to allow the driver to use client load balancing in its attempts to connect to primary and alternate database servers. In this case, the driver attempts to connect to the database servers in random order. See "Using Client Load Balancing" for more information.
If this check box is not selected (the default), client load balancing is not used and the driver connects to each database server based on its sequential order (primary server first, then, alternate servers in the order they are specified).
NOTE: This option has no effect unless alternate servers are defined for the Alternate Servers connection option.
The Load Balancing option is an optional setting that you can use in conjunction with connection failover. See "Configuring Connection Failover" for a discussion of connection failover and for information about other connection options that you can set for this feature.
Alternate Servers: Type a list of alternate database servers to which the driver will try to connect if the primary database server is unavailable. Specifying a value for this option enables connection failover for the driver. See "Using Connection Failover" for a discussion of connection failover.
The value you specify must be in the form of a string that defines the physical location of each alternate server. All of the other required connection information for each alternate server is the same as what is defined for the primary server connection.
For the Informix Wire Protocol driver, you must specify the database, host name, port number, and the server name. The string has the format:
(Database=databasename:HostName=hostvalue:
PortNumber=portvalue:ServerName=servervalue[, . . .])
For example, the following Alternate Servers value defines two alternate database servers for connection failover:
(Database=Infdb1:HostName=Informixhost1:PortNumber=5177:
ServerName=accounting1, Database=Infdb2:
HostName=Informixhost2:PortNumber=5178:
ServerName=accounting2)
See "Configuring Connection Failover" for information about other connection options that you can set for this feature.
Connection Retry Count: Type a value to specify the number of times the driver tries to connect to the primary server and, if configured, to the alternate servers after the initial unsuccessful attempt. See "Using Connection Retry" for more information about this feature.
Valid values are integers from 0 to 65535. When set to 0 (the default), the driver does not try to connect after the initial unsuccessful attempt.
If a connection is not established during the retry attempts, the driver returns an error that is generated by the last server to which it tried to connect.
This option and the Connection Retry Delay connection option, which specifies the wait interval between attempts, can be used in conjunction with connection failover.
See "Configuring Connection Failover" for a discussion of connection failover and for information about other connection options that you can set for this feature.
Connection Retry Delay: Type a value to specify the number of seconds that the driver waits after the initial unsuccessful connection attempt before retrying a connection to the primary server and, if specified, to the alternate servers.
Valid values are integers from 0 to 65535. The default value is 3 (seconds). When set to 0, there is no delay between retries.
NOTE: This option has no effect unless the Connection Retry Count connection option is set to an integer value greater than 0.
This option and the Connection Retry Count connection option, which specifies the number of times the driver tries to connect after the initial unsuccessful attempt, can be used in conjunction with connection failover.
NOTE: If you are configuring alternate servers for use with the connection failover feature, be aware that the Test Connect button tests only the primary server, not the alternate servers.