4 Oracle Database Client Postinstallation Tasks

This chapter describes how to complete postinstallation tasks after you have installed the Oracle database client software. It includes information about the following topics:

Required Postinstallation Tasks
Recommended Postinstallation Tasks
Required Product-Specific Postinstallation Tasks

You must perform the tasks listed in "Required Postinstallation Tasks". Oracle recommends that you perform the tasks listed in "Recommended Postinstallation Tasks" after all installations.

If you install and intend to use any of the products listed in "Required Product-Specific Postinstallation Tasks", then you must perform the tasks listed in the product-specific subsections.

Note:

This chapter describes basic configuration only. Refer to Oracle Database Administrator's Reference for Linux and UNIX-Based Operating Systems, Oracle Database Administrator's Guide and product-specific administration and tuning guides for exhaustive configuration and tuning information.

4.1 Required Postinstallation Tasks

You must perform the tasks described in the following sections after completing an installation:

Downloading and Installing Patches
Updating Instant Client
Connecting with Instant Client

4.1.1 Downloading and Installing Patches

Check the My Oracle Support website for required patches for the installation.

Note:

You cannot update Instant Client by downloading a patch. Use the procedure under "Updating Instant Client" to update Instant Client.

To download required patches:

Use a web browser to view the My Oracle Support website:
```
https://support.oracle.com/
```
Log in to My Oracle Support.

Note:
If you are not a My Oracle Support registered user, click Register here and follow the registration instructions.
On the main My Oracle Support page, click the Patches and Updates tab.
In the Patch Search group, select Product or Family (Advanced).
In the Product field, select Oracle Database.
In the Release field select the release number. For example, Oracle 11.2.0.3.1.
Click Search.
Any available patch updates are displayed in the Patch Search page.
Select the patch number and click ReadMe. The README page is displayed and contains information about the patch set and how to apply the patches to your installation.
Return to the Patch Search page, click Download, and save the file on your system.
Use the unzip utility provided with Oracle Database 11g release 1 (11.1) to uncompress the Oracle patch updates that you downloaded from My Oracle Support. The unzip utility is located in the $ORACLE_HOME/bin directory.

4.1.2 Updating Instant Client

To update Instant Client:

Download Instant Client from Oracle Technology Network:

http://www.oracle.com/technetwork/database/features/instant-client/index-097480.html
If you want to place the files in the existing directory, then ensure that the directory is empty.

If you want to place the files into a different directory (and remove the previous files), ensure that you update the PATH environment variable setting to reflect the new location.

Note:

A restriction on Instant Client or Instant Client Light is that you cannot perform patch upgrades using the opatch utility because the Instant Client installation does not create an inventory, which the patch upgrade process must access for patch upgrades. The absence of an inventory also means that the installed intern patch reporting and conflict detection before a patch attempt are not possible.

4.1.3 Connecting with Instant Client

If you installed the Instant Client installation type, you can configure users' environments to enable dynamically linked client applications to connect to a database as follows:

Set the appropriate shared library path environment variable for the platform to specify the directory that contains the Instant Client libraries. For the Instant Client installation type, this directory is the Oracle home directory that you specified during the installation, for example:
```
/u01/app/oracle/product/11.2.0/client_1
```
Use one of the following methods to specify database connection information for the client application:
- Specify a SQL connect URL string using the following format:
```
//host:port/service_name
```
- Set the TNS_ADMIN environment variable to specify the location of the tnsnames.ora file and specify a service name from that file.
- Set the TNS_ADMIN environment variable and set the TWO_TASK environment variable to specify a service name from the tnsnames.ora file.

Note:

You do not have to specify the ORACLE_HOME environment variable.

4.2 Recommended Postinstallation Tasks

Oracle recommends that you perform the tasks described in the following section after completing an installation:

Configuring Instant Client Light
Creating a Backup of the root.sh Script
Connecting Instant Client or Instant Client Light to an Oracle Database
Setting Up User Accounts
Setting the NLS_LANG Environment Variable
Generating the Client Static Library

4.2.1 Configuring Instant Client Light

When you install Instant Client, the Instant Client libraries are installed under the ORACLE_HOME directory and the Instant Client Light specific library is installed under the ORACLE_HOME/light directory. To configure Instant Client Light, you must replace the ORACLE_HOME/libociei.so file with the ORACLE_HOME/light/libociicus.so file.

After replacing the library file, you must set the LD_LIBRARY_PATH environment variable to point to the location of the Instant Client shared library files.

4.2.2 Creating a Backup of the root.sh Script

Oracle recommends that you back up the root.sh script after you complete an installation. If you install other products in the same Oracle home directory, then Oracle Universal Installer updates the contents of the existing root.sh script during the installation. If you require information contained in the original root.sh script, then you can recover it from the backed up root.sh file.

4.2.3 Connecting Instant Client or Instant Client Light to an Oracle Database

Before you can connect Instant Client (including Instant Client Light) to an Oracle database, ensure that the LD_LIBRARY_PATH environment variable specifies the directory that contains the Instant Client libraries. This directory is the ORACLE_HOME directory that you specified during installation.

For example, the shared libraries for Instant Client or Instant Client Light (if you have configured Instant Client Light), are in:

/u01/app/oracle/product/11.2.0/client_1

After you have checked the LD_LIBRARY_PATH environment variable, you can use any of the following methods to specify Oracle Database connection information for client applications:

Specifying a Connection by Using the Easy Connect Naming Method
Specifying a Connection by Configuring a tnsnames.ora File
Specifying a Connection Using an Empty Connect String and TWO_TASK

4.2.3.1 Specifying a Connection by Using the Easy Connect Naming Method

You can specify a connection address to an Oracle Database directly from a client application, without having to configure a tnsnames setting for the Instant Client. This method is convenient as you do not have to create and manage a tnsnames.ora file. However, the application users must specify the host name and port number when they want to log in to the application.

For example, if you run SQL*Plus on the client computer and want to connect to the sales_us database, which is located on a server whose host name is shobeen and port number is 1521, then you can log in as follows:

sqlplus system/admin@//shobeen:1521/sales_us

Similarly, in the application code, you can use Oracle Call Interface net naming methods to create the Instant Client-to-Oracle Database connection. For example, the following formats in the OCIServerAttach() call specify the connection information:

Specify a SQL connect URL string using the following format:
```
//host[:port][/service_name]
```
For example:
```
//shobeen:1521/sales_us
```
Alternatively, you can specify the SQL connect information as an Oracle Net keyword-value pair. For example:
```
"(DESCRIPTION=(ADDRESS=(PROTOCOL=tcp) (HOST=shobeen) (PORT=1521))
(CONNECT_DATA=(SERVICE_NAME=sales_us)))"
```
See Also:
Oracle Call Interface Programmer's Guide for more information on using Oracle Call Interface Instant Client

4.2.3.2 Specifying a Connection by Configuring a tnsnames.ora File

By default, when you install Instant Client, Oracle Universal Installer does not include a sample tnsnames.ora file nor the Oracle Net Configuration Assistant utility normally used to create it. However, to shield users from having to specify actual host names and port numbers, consider using a tnsnames.ora file to set the Client-to-Oracle Database connection.

You can create the tnsnames.ora file manually by copying and modifying a version of this file from another Oracle installation, or you can use Oracle Net Configuration Assistant to create and manage it for you.

To install Oracle Net Configuration Assistant:

Run Oracle Universal Installer.
Select the Custom installation type.
In the Available Product Components screen, select Oracle Net Listener.
In the Summary screen, click Install, click Exit, and then click Yes to exit Oracle Universal Installer.

On each client computer, configure either of the following settings:

Set the TNS_ADMIN environment variable to specify the location of the tnsnames.ora file and specify a service name from that file.
Place the tnsnames.ora file in the $ORACLE_HOME/network/admin directory, and ensure that the ORACLE_HOME environment has been set to this Oracle home.

See Also:
Oracle Call Interface Programmer's Guide for more information on Oracle Call Interface Instant Client connection strings

4.2.3.3 Specifying a Connection Using an Empty Connect String and TWO_TASK

You can set the connect string to an empty connect string (""), and then set the TWO_TASK environment variable to one of the following values:

A direct address, as described under "Specifying a Connection by Using the Easy Connect Naming Method"
Oracle Net keyword-value pair
A tnsnames.ora entry and TNS_ADMIN is set to the location of tnsnames.ora
A tnsnames.ora entry and the following:
- tnsnames.ora file located in $ORACLE_HOME/network/admin
- The ORACLE_HOME environment variable set to this Oracle home

This method allows the applications to specify internally a connection string if the application code itself uses an empty connection string. The benefit of an empty connect string is that the application itself does not have to specify the tnsnames.ora entry. Instead, when a user starts the application, the location of the database is determined by a script or the environment, depending on where you have set the TWO_TASK environment variable. The disadvantage of using empty strings is that you must configure this additional information in order for the application to connect to the database.

4.2.4 Setting Up User Accounts

For information about setting up additional user accounts, refer to Oracle Database Administrator's Reference for Linux and UNIX-Based Operating Systems.

4.2.5 Setting the NLS_LANG Environment Variable

NLS_LANG is an environment variable that specifies the locale behavior for Oracle software. This variable sets the language and territory used by the client application and the database user session. It also declares the character set of the client, which is the character set of data entered or displayed by an Oracle client program, such as SQL*Plus.

4.2.6 Generating the Client Static Library

The client static library (libclntst11.a) is not generated during installation. If you want to link the applications to the client static library, you must first generate it as follows:

Switch user to oracle.
Set the ORACLE_HOME environment variable to specify the Oracle home directory used by the Oracle Database installation. For example:
- Bourne, Bash, or Korn shell:
```
$ ORACLE_HOME=/u01/app/oracle/product/11.2.0/client_1 
$ export ORACLE_HOME
```
- C shell:
```
% setenv ORACLE_HOME /u01/app/oracle/product/11.2.0/client_1
```
Enter the following command:
```
$ $ORACLE_HOME/bin/genclntst
```

4.3 Required Product-Specific Postinstallation Tasks

The following sections describe postinstallation tasks that you must perform if you install and intend to use the products mentioned:

Configuring Oracle Net Services
Configuring Oracle Precompilers

Note:

You must perform postinstallation tasks only for products that you intend to use.

4.3.1 Configuring Oracle Net Services

If you have an earlier release of Oracle software installed on this system, you might want to copy information from the Oracle Net tnsnames.ora and listener.ora configuration files from the earlier release to the corresponding files for the new release.

Note:

The default location for the tnsnames.ora and listener.ora files is the $ORACLE_HOME/network/admin/ directory. However, you can also use a central location for these files.

If necessary, you can also add connection information for additional database instances to the new file.

4.3.2 Configuring Oracle Precompilers

This section describes postinstallation tasks for Oracle precompilers:

Configuring Pro*C/C++
Configuring Pro*FORTRAN

Note:

All precompiler configuration files are located in the $ORACLE_HOME/precomp/admin directory.

4.3.2.1 Configuring Pro*C/C++

Verify that the PATH environment variable setting includes the directory that contains the C compiler executable.

The following table shows the default directories and the appropriate command to verify the path setting of the compiler:

Table 4-1 C/C++ Compiler Directory

Path	Command
`/usr/bin`	`$ which gcc`
`/opt/ansic/bin`	`$ which cc`

4.3.2.2 Configuring Pro*FORTRAN

Verify that the PATH environment variable setting includes the directory that contains the FORTRAN compiler executable. You can verify the path setting by using the xlf whichf90 command.