The power of Oracle10g Remote Stored Functions!!

 Author: Burleson

Oracle has enabled database administrators to refer to remote functions stored in a non-Oracle database within the SELECT statement. The hs_call_name parameter refers to this feature.

hs_call_name parameter:

The hs_call_name parameter is specified in the heterogeneous services initialization parameter file.

This file contains configuration settings stored as a text file.

The heterogeneous services initialization parameters give the DBA a means of fine-tuning to optimize performance and memory utilization for the gateway and the Heterogeneous Services component.

It also enables the DBA to tell the gateway services and thereby, heterogeneous services how the non-Oracle system has been configured.

These parameters give heterogeneous services information about the configurable properties of the non-Oracle database system.

v$hs_parameter:

The view v$hs_parameter can be used to monitor the heterogeneous services initialization parameters. Users can set initialization parameters in the gateway initialization files.

There is a heterogeneous services initialization file for each gateway instance. The name of the file is initsid.ora, where sid is the Oracle system identifier used for the gateway.

Generic connectivity:

The heterogeneous services initialization file is located in the directory $ORACLE_HOME/hs/admin for generic connectivity.

Non-oracle database system transparent gateways:

The heterogeneous services initialization file is located in directories named with the naming convention in case of specific non-oracle database system transparent gateways

$ORACLE_HOME/product_name/admin

where the product_name variable is the name of the database system.

For example, the Sybase gateway initialization file is located in the directory $ORACLE_HOME/tg4sybs/admin.

Setting the initialization parameters:

The heterogeneous services initialization files contain a list of initialization parameter settings, each of which should be on an individual line. The syntax to set the initialization parameters is as under

[set] [private] parameter = parameter_value

set and private keywords:

The set and private keywords are optional.

When the set keyword is present, the variable will also be set in the environment.

When the private keyword is present, the parameter will not be uploaded to the server.

In general, Oracle recommends that the private keyword not be used. The only exception is if the initialization parameter value contains sensitive information (such as a password) that shouldn't be sent over the network.

Initialization parameter syntax:

The following rules apply in the initialization parameter syntax.

• All keywords (SET, PRIVATE, and IFILE) are case insensitive.
• Initialization parameter names and values are case sensitive. Most initialization parameter names are uppercase.
• String values for heterogeneous services parameters must be lowercase.
• Exceptions to these rules are explicitly noted.

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