Net8 Administrator's Guide
Release 8.1.6

Part Number A76933-01





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Access Control List (ACL)

The group of access directives that you define. The directives grant levels of access to specific data for specific clients and/or groups of clients.


See Access Control List (ACL).

access control

See Net8 access control.


A unique network location used to identify a network object, such as a listener address, Oracle Connection Manager, or Oracle Names server. Addresses have a specific format and must be unique.

administrative context

A directory entry under which an Oracle Context resides. An administrative context can be a directory naming context. During directory access configuration, clients are configured with an administrative context in the directory configuration file (ldap.ora). The administrative context specifies the location of the Oracle Context in the directory whose entries a client expects to access

administrative region

An organizational entity for administering Net8 network components. Each administrative region includes:


An alternative name for an existing network object. Once an alias is created, it is resolved to the same name as the initial network object. An Oracle Names server stores aliases for any defined net service name, database server or database link.


See Net8 Open.

ASCII character set

Stands for American Standard Code for Information Interchange character set, a convention for representing alphanumeric information using digital data. The collation sequence used by most computers with the exception of IBM and IBM-compatible computers.


A piece of information that describes some aspect of an entry. An entry comprises a set of attributes, each of which belongs to an object class. Moreover, each attribute has both a type--which describes the kind of information in the attribute--and a value--which contains the actual data.

authentication method

A security method that enables you to have high confidence in the identity of users, clients, and servers in distributed environments. Network authentication methods can also provide the benefit of single sign-on for users. The following authentication methods may be supported, depending on whether or not Oracle Advanced Security is installed:


Bequeath protocol

If the listener and server exist on the same node, the listener may create or spawn dedicated servers as connect requests are received. Dedicated servers are committed to one network session only and exist for the duration of that network session. The sequence of events that occur when the listener creates a dedicated server process and passes or "bequeaths" control of a network session to it.



Memory that stores recently-accessed data to so that subsequent requests to access the same data can be processed quickly.


Cell Directory Services. See Cell Directory Services (CDS).

Cell Directory Services (CDS)

An external naming method that enables users to transparently use Oracle tools and applications to access Oracle8i databases in a Distributed Computing Environment (DCE) environment.

central administration

An Oracle Names network where network management consists of one administrative region for the entire network. With central administration, all Oracle Names servers know about one another and about all the services in the network. Contrast with delegated administration.


A user, software application, or computer that requests the services, data, or processing of another application or computer. In a two-task environment, the client is the user process. In a network environment, the client is the local user process and the server may be local or remote.

client load balancing

Load balancing, whereby a client can randomly choose between the listeners for its connect requests if more than one listener services a single database. This randomization enables all listeners to share the burden of servicing incoming connect requests.

client profile

The properties of a client, which may include the preferred order of naming methods, client and server logging and tracing, the domain from which to request names, and other client options for Oracle Names and Oracle Advanced Security.

client-server architecture

Software architecture based on a separation of processing between two CPUs, one acting as the client in the transaction, requesting and receiving services, and the other as the server that provides services in a transaction.

cman.ora file

A configuration file that specifies protocol addresses for incoming requests and administrative commands, as well as Oracle Connection Manager parameters and Net8 access control rules.

configuration files

Files that are used to identify and characterize the components of a network. Configuration is largely a process of naming network components and identifying relationships among those components.

connect data

A portion of the connect descriptor that defines the destination database service name or Oracle System Identifier (SID). In the example below, SERVICE_NAME defines a database service called

  (address= (protocol=tcp)(host=sales-pc)(port=1521)
connect descriptor

A specially formatted description of the destination for a network connection. A connect descriptor contains destination service and network route information.

The destination service is indicated by using its service name for Oracle release 8.1 database or its Oracle System Identifier (SID) for Oracle release 8.0 or version 7 databases. The network route provides, at a minimum, the location of the listener through use of a network address.

connect identifier

A net service name or service name, that resolves to a connect descriptor. Users initiate a connect request by passing a user name and password along with a connect identifier in a connect string for the service to which they wish to connect, for example:

CONNECT username/password@connect_identifier

connect-time failover

A client connect request is forwarded to a another listener if first listener is not responding. Connect-time failover is enabled by service registration, because the listener knows if an instance is up prior to attempting a connection.


An interaction between two processes on a network. Connections are originated by an initiator (client), who requests a connection with a destination (server).

connection concentration

A feature of Oracle Connection Manager that consolidates multiple connection requests from clients to establish a single connection to a server in order to conserve server resources.

connection load balancing

Load balancing, whereby the number of active connections among various instances and dispatchers for the same service are balanced. This enables listeners to make their routing decisions based on how many connections each dispatcher has and on how loaded the nodes that the instances run.

connection pooling

A resource utilization and user scalability feature that enables you to maximize the number of physical network connections to a multi-threaded server. A feature of Oracle Connection Manager that consolidates multiple connection requests from clients to establish a single connection to a server in order to conserve server resources.

connection request

A notification sent by an initiator and received by a listener that indicates that the initiator wants to start a connection.

connect string

Information the user passes to a service to connect, such as user name, password and net service name. For example:

CONNECT username/password@net_service_name


data packet

See packet.

database administrator (DBA)

(1) A person responsible for operating and maintaining an Oracle Server or a database application. (2) An Oracle username that has been given DBA privileges and can perform database administration functions. Usually the two meanings coincide. Many sites have multiple DBAs.

database link

A network object stored in the local database or in the network definition that identifies a remote database, a communication path to that database, and optionally, a username and password. Once defined, the database link is used to access the remote database.

A public or private database link from one database to another is created on the local database by a DBA or user.

A global database link is created automatically from each database to every other database in a network with Oracle Names. Global database links are stored in the network definition.

See also global database link, private database link, and public database link.

decentralized administration

See delegated administration.

dedicated server

A server that requires a dedicated server process for each user process. There is one server process for each client. Net8 sends the address of an existing server process back to the client. The client then resends its connect request to the server address provided. Contrast with multi-threaded server (MTS).

default domain

The domain domain within which most client requests take place. It could be the domain where the client resides, or it could be a domain from which the client requests network services often. Default domain is also the client configuration parameter that determines what domain should be appended to unqualified network name requests. A name request is unqualified if it does not have a "." character within it.

delegated administration

A Net8 network where network management is delegated to one or more administrative regions below the root administrative region. Also referred to as distributed or decentralized administration. Contrast with central administration.

delegated administrative region

A region hierarchically below the root administrative region. Any region other than the root administrative region.


The client that is the endpoint of a connection. The initiator of the connection requires some data or service of the destination.

Directory Information Tree (DIT)

A hierarchical tree-like structure in a directory sever of the Distinguished Names (DNs) of the entries.

directory naming

A naming method that resolves a database service or net service name to a connect descriptor, stored in a central directory server.

A directory provides central administration of database services and net service names, reducing the work effort associated with adding or relocating services. Although net service names can be configured to alias a service, the directory can refer to a database service directly without using a net service name. To further aid with configuration ease, the database service is automatically added as an entry to the directory during installation.

directory naming context

A subtree which is of significance within a directory server. It is usually the top of some organizational subtree. Some directories only allow one such context which is fixed; others allow none to many to be configured by the directory administrator.

directory sever

A LDAP-compliant directory server that is accessed with the Lightweight Directory Access Protocol (LDAP). A directory can provide centralized storage and retrieval of database network components, user and corporate policies preferences, user authentication and security information, replacing client-side and server-side localized files.


A process that enables many clients to connect to the same server without the need for a dedicated server process for each client. A dispatcher handles and directs multiple incoming network session requests to shared server processes. See also multi-threaded server (MTS).

Distinguished Name (DN)

Name of entry in a directory sever. The DN specifies where the entry resides in the LDAP directory hierarchy, much the way a directory path specifies the exact location of a file.

distributed administration

See delegated administration.

distributed processing

Division of front-end and back-end processing to different computers. Net8 supports distributed processing by transparently connecting applications to remote databases.


Any tree or subtree within the Domain Name System (DNS) namespace. Domain is most commonly used to refer to a group of computers whose host names share a common suffix, the domain name.

Domain Name System (DNS)

Domain Name System (DNS) is a system for naming computers and network services that is organized into a hierarchy of domainss. DNS is used in TCP/IP networks to locate computers through user-friendly names. DNS resolves a friendly name into an IP address, which is understood by computers.

For Net8, DNS translate the host name in a TCP/IP address into an IP address.

domestic domains

The set of domains that are managed within a given administrative region. Domains are only domestic relative to a region; they are never domestic in any absolute sense. Also referred to as local domains.


Domain Name System. See Domain Name System (DNS).


error message

A message from a computer program informing you of a potential problem or condition preventing program or command execution.

enterprise role

An enterprise role is analogous to a regular database role, except that it spans authorization on multiple databases. An enterprise role is a category of roles that define privileges on a particular database. A enterprise role is created by a Database Administrator of a particular database. An enterprise role can be granted or revoked to one or more enterprise users. The information for granting and revoking these roles is also stored in the directory. In addition to creating global roles, a Database Administrator can also grant roles and privileges to a database schema. Everyone sharing a schema gets these local roles and privileges in addition to the enterprise roles.

Each enterprise user has a unique identity across an enterprise. Enterprise users connect to individual databases via a schema. Enterprise users are assigned enterprise roles which determine their access privileges on databases.

enterprise user

Each enterprise user has a unique identity across an enterprise. Enterprise users connect to individual databases via a schema. Enterprise users are assigned enterprise roles which determine their access privileges on databases.


The building block of a directory, it contains information about an object of interest to directory users.

external naming

A net service name resolution that uses a supported third-party naming service, such as NIS or NDS.

external procedures

Functions or procedures written in a third-generation language (3GL) that can be called from PL/SQL code. Only C is supported for external procedures.



See connect-time failover.

firewall support

See Net8 access control.

flat naming model

An Oracle Names infrastructure in which there is only one domain. All names must be unique within that domain.

foreign domains

The set of domains not managed within a given administrative region. Domains are only foreign relative to a region; they are not foreign in any absolute sense. A network administrator typically defines foreign domains relative to a particular region to optimize Names Server caching performance.


General Inter-ORB Protocol (GIOP)

A presentation layer type that is used in Java option connections to provide messaging.

global database link

A database link that links each database in a network to all other databases. This enables any user of any database in the network to specify a global object name in a SQL statement or object definition. An Oracle Names server can store global database links.

A database link that links each database in a network to all other databases. This enables any user of any database in the network to specify a global object name in a SQL statement or object definition.

global database name

The full name of the database which uniquely identifies it from any other database. The global database name is of the form "database_name.database_domain", for example,

The database name portion, sales, is a simple name you wish to call your database. The database domain portion,, specifies the database domain in which the database is located, making the global database name unique. When possible, Oracle recommends that your database domain mirror the network domain.

The global database name is the default service name of database, as specified by the SERVICE_NAMES parameter in the initialization parameter file.


Heterogeneous Services

An integrated component that provides the generic technology for accessing non-Oracle systems from the Oracle server. Heterogeneous Services enables you to:

hierarchical naming model

An infrastructure in which names are divided into multiple hierarchically-related domains. For Oracle Names, hierarchical naming model can be used with either central or delegated administration.

host naming

A net service name resolution that enables users in a TCP/IP environment to resolve net service names via their existing name resolution service. This name resolution service might be Domain Name System (DNS), Network Information Service (NIS) or simply a centrally-maintained set of /etc/hosts files. Host Naming enables users to connect to an Oracle server by simply providing the server computer's host name or host name alias. No client configuration is required to take advantage of this feature. This method is recommended for simple TCP/IP environments.


initialization parameter file

File that contains information to initialize the database and instances.


An instance of the running Oracle8i software referencing the database. When a database is started on a database server (regardless of the type of computer), Oracle allocates a memory area called the System Global Area (SGA) and starts one or more Oracle processes. This combination of the SGA and the Oracle processes is called an instance. The memory and processes of an instance efficiently manage the associated database's data and serve the database users. You can connect to any instance to access information within a parallel server database.

Inter-ORB Protocol (IIOP)

An implementation of General Inter-ORB Protocol (GIOP) over TCP/IP or TCP/IP with SSL for connections to Oracle8i JServer.

Interprocess Communication

A protocol used by client applications the reside on the same node as the listener to communicate with the database.

IIOP Clients

Clients that use the General Inter-ORB Protocol (GIOP) presentation to access the Java option. These clients include:

IP address

Used to identify a node on a network. Each machine on the network is assigned a unique IP address, which is made up of the network ID, plus a unique host ID. This address is typically represented in dotted-decimal notation, with the decimal value of each octet separated by a period (for example

See Interprocess Communication.


Java Database Connectivity (JDBC) Drivers

Drivers that provide Java programmers access to an Oracle database.


keyword-value pair

The combination of a keyword and a value, used as the standard unit of information in connect descriptors and many configuration files. Keyword-value pairs may be nested; that is, a keyword may have another keyword-value pair as its value.



Lightweight Directory Access Protocol. The framework of design conventions supporting industry-standard directory severs.

LDAP Data Interchange Format (LDIF)

The set of standards for formatting an input file for any of the LDAP command line utilities.

ldap.ora file

A file created by the Net8 Configuration Assistant that contains the following directory access information:

The ldap.ora file resides in $ORACLE_HOME/network/admin on UNIX platforms and ORACLE_HOME\network\admin on Windows platforms.

link qualifier

A qualifier appended to a global database link to provide alternate settings for the database user name and password credentials. For example, a link qualifier of emp can be appended to a global database link of


A process that resides on the server whose responsibility is to listen for incoming client connection requests and manage the traffic to the server.

Every time a client (or server acting as a client) requests a network session with a server, a listener receives the actual request. If the client's information matches the listener's information, the listener grants a connection to the server.

listener.ora file

A configuration file for the listener that identifies the:

The listener.ora file typically resides in $ORACLE_HOME/network/admin on UNIX platforms and ORACLE_HOME\network\admin on Windows NT.

An Oracle release 8.1 databases does not require identification of the database service because of service registration. However, static service configuration is required for an Oracle release 8.1 databases if you plan to use Oracle Enterprise Manager.

Listener Control Utility (LSNRCTL)

A utility included with Net8 to control various listener functions, such as to start, stop, and get the status of the listener.

load balancing

A feature by which client connections are distributed evenly among multiple listeners, dispatchers, instances, and nodes so that no single component is overloaded.

Net8 supports client load balancing and connection load balancing.

local naming

A net service name resolution that locates network addresses by using information configured and stored on each individual client's tnsnames.ora file. Local naming is most appropriate for simple distributed networks with a small number of services that change infrequently.

location transparency

A distributed database characteristic that enables applications to access data tables without knowing where they reside. All data tables appear to be in a single database, and the system determines the actual data location based on the table name. The user can reference data on multiple nodes in a single statement, and the system automatically and transparently routes (parts of) SQL statements to remote nodes for execution if needed. The data can move among nodes with no impact on the user or application.


A feature in which errors, service activity, and statistics are written to a log file. The log file provides additional information for an administrator when the error message on the screen is inadequate to understand the failure. The log file, by way of the error stack, shows the state of the software at various layers.

See also tracing.

loopback test

A connection from the server back to itself. Performing a successful loopback verifies that Net8 is functioning on the server side.

LU6.2 protocol

Logical Unit Type 6.2. A protocol enables an Oracle application on a PC to communicate with an Oracle database. This communication occurs over an System Network Architecture (SNA) network with the Oracle database on a host system that supports Advanced Program-to-Program Communication (APPC) architecture.



Files used by the Network Information Service (NIS) ypserv program to handle name requests.

Microsoft's Active Directory

A LDAP-compliant directory service included with the Windows 2000 Server. It stores information about objects on the network, and makes this information available to users and network administrators. Active Directory also provides users access to resources on the network using a single logon process.

Active Directory can be configured as a directory naming method to store service information that clients can access.


See multi-threaded server (MTS).

multi-protocol support

A feature of Oracle Connection Manager that enables a client and server with different networking protocols to communicate with each other. This feature replaces functionality previously provided by the Oracle Multi-Protocol Interchange with SQL*Net version 2.

multi-threaded server (MTS)

A server that is configured to allow many user processes to share very few server processes, so the number of users that can be supported is increased. With MTS configuration, many user processes connect to a dispatcher. The dispatcher directs multiple incoming network session requests to a common queue. An idle shared server process from a shared pool of server processes picks up a request from the queue. This means a small pool of server processes can server a large amount of clients. Contrast with dedicated server.


Combining multiple sessions for transmission over a single transport connection in order to conserve the operating system's resources. See also connection concentration


names.ora file

A configuration file that contains parameter settings for an Oracle Names server.

Named Pipes protocol

A high-level interface protocol providing interprocess communications between clients and servers (distributed applications). Named Pipes enables client/server conversation over a network using Named Pipes.

naming method

The method used by a client application to resolve a connect identifier to a connect descriptor when attempting to connect to a database service. Net8 provides five naming methods:

naming model

The set and structure of domains within which names can be allocated.

In a flat naming model, there is a single domain.

In a hierarchical naming model, the highest level is the root domain, and all other domains are hierarchically related.

NDS authentication

An authentication method that enables a client single login access to a multi-server and multi-database network under a single NDS directory tree.


See Novell Directory Services (NDS).

net service name

A simple name for a service that resolves to a connect descriptor. Users initiate a connect request by passing a user name and password along with a net service name in a connect string for the service to which they wish to connect:

CONNECT username/password@net_service_name

Depending on your needs, net service names can be stored in a variety of places, including:


Oracle's remote data access software that enables both client-server and server-server communications across any network. Net8 supports distributed processing and distributed database capability. Net8 runs over and interconnects many communications protocols. Net8 is backward compatible with SQL*Net version 2.

Net8 access control

A feature of Oracle Connection Manager that sets rules for denying or allowing certain clients to access designated servers. Also known as firewall support.

Net8 Assistant

A graphical user interface tool that combines configuration abilities with component control to provide an integrated environment for configuring and managing Net8. It can be used on either the client or server.

You can use Net8 Assistant to configure the following network components:

Net8 Configuration Assistant

A post-installation tool that configure basic network components after installation, including:

Net8 Open

The application program interface (API) to Net8 that enables programmers to develop both database and non-database applications that make use of the Net8 network already deployed in their environment. Net8 Open provides applications a single common interface to all industry standard network protocols.


A group of two or more computers linked together through hardware and software to allow the sharing of data and/or peripherals.

network administrator

The person who performs network management tasks such as installing, configuring, and testing network components. The administrator typically maintains the configuration files, connect descriptors and service names, aliases, and public and global database links.

network character set

As defined by Oracle, the set of characters acceptable for use as values in keyword-value pairs (that is, in connect descriptors and configuration files). The set includes alphanumeric upper- and lowercase, and some special characters.

Network Information Service (NIS)

Sun Microsystems' Yellow Pages (yp) client-server protocol for distributing system configuration data such as user and host names between computers on a network.

Network Interface (NI)

A network layer that provides a generic interface for Oracle clients, servers, or external processes to access Net8 functions. The NI layer handles the "break" and "reset" requests for a connection.

See listener.

network object

Any service that can be directly addressed on a network; for example, a listener or a Oracle Names server.

network protocol

See Oracle Protocol.

Network Program Interface (NPI)

An interface for server-to-server interactions that performs all of the functions that the OCI does for clients, allowing a coordinating server to construct SQL requests for additional servers.

network service

In an Oracle application network, a service performs tasks for its service consumers; for example, a Names Server provides name resolution services for clients.

Network Session (NS)

NS is a session layer types that is used in typical Net8 connection to establish and maintaining the connection between a client application and server.


Network Interface


Network Information Service. See Network Information Service (NIS).


Network Naming (Oracle Names)


A computer or terminal that is part of a network.

Novell Directory Services (NDS)

A distributed computing infrastructure that stores information about network resources on your network. NDS provides easy network access regardless of the user's physical location or the location of needed resources.

Using NDS, you can simplify network administration by using objects to represent any network resource in the network file system.


See Network Program Interface (NPI).


Network Routing


Network Session. See Network Session (NS).


Network Transport. See transport.


object class

A named group of attributes. When you want to assign attributes to an entry, you do so by assigning to that entry the object classes that hold those attributes.

All objects in the same object class share the same attributes.


Oracle Call Interface. See Oracle Call Interface (OCI).


See Oracle Program Interface (OPI).

Open Systems Interconnection (OSI)

A model of network architecture developed by ISO as a framework for international standards in heterogeneous computer network architecture.

The OSI architecture is split between seven layers, from lowest to highest: 1 physical layer, 2 data link layer, 3 network layer, 4 transport layer, 5 session layer, 6 presentation layer, 7 application layer. Each layer uses the layer immediately below it and provides a service to the layer above.

Oracle Advanced Security

A product that provides a comprehensive suite of security features to protect enterprise networks and securely extend corporate networks to the Internet. Oracle Advanced Security provides a single source of integration with network encryption and authentication solutions, single sign-on services, and security protocols. By integrating industry standards, it delivers unparalleled security to the network.

Oracle Call Interface (OCI)

An application programming interface (API) that enables you to create applications that use the native procedures or function calls of a third-generation language to access an Oracle database server and control all phases of SQL statement execution. OCI supports the datatypes, calling conventions, syntax, and semantics of a number of third-generation languages including C, C++, COBOL and FORTRAN.

Oracle Connection Manager

A router through which a client connection request may be sent either to its next hop or directly to the database server. Clients who route their connection requests through a Connection Manager can then take advantage of the connection concentration, Net8 access control, or multi-protocol support features configured on that Connection Manager.

Oracle Connection Manager Control Utility (CMCTL)

A utility included with Net8 to control various functions, such as to start, stop, and get the status of the Oracle Connection Manager.

Oracle Context

A RDN of cn=OracleContext, under which all Oracle software relevant information is kept, including entries for directory naming and enterprise user security.

There may be one or more than one Oracle Context in a directory. An Oracle Context can be associated with a directory naming context.

Oracle Database Configuration Assistant

A tool that enables you to create, delete, and modify a database.

Oracle Internet Directory

A directory service implemented as an application on the Oracle release 8.1 database. It enables retrieval of information about dispersed users and network resources. It combines Lightweight Directory Access Protocol (LDAP) Version 3, the open Internet standard directory access protocol, with the high performance, scalability, robustness, and availability of the Oracle8i Server.

Oracle Names

An Oracle directory service made up of a system of Oracle Names servers that provide name-to-address resolution for each Net8 service on the network.

Oracle Names Control Utility (NAMESCTL)

A utility included with Oracle Names to control various functions for Oracle Names servers, such as to start, stop, and get the status of an Oracle Names server.

Oracle Names server

A server that uses Oracle Names to store a service's network address along with its simple name so that client applications can request connections with simple names, rather than lengthy addresses.

Oracle Program Interface (OPI)

A networking layer that is responsible for responding to each of the possible messages sent by OCI. For example, an OCI request to fetch 25 rows would have an OPI response to return the 25 rows once they have been fetched.

Oracle Protocol

A set of rules that defines how data is transported across networks. There are several industry standard transport protocols, such as TCP/IP and SPX.

Oracle Rdb

A database for Digital's 64-bit platforms. Because Oracle Rdb has its own listener, the client interacts with Rdb in the same manner as it does with an Oracle database.

Oracle schema (as it relates to LDAP)

A set of rules that determine what can be stored in directory sever. Oracle has its own schema that is applied to many types of Oracle entries, including Net8 entries. The Oracle schema for Net8 entries includes the attributes the entries may contain.

Oracle System Identifier (SID)

A name that identifies a specific instance of a running pre-release 8.1 Oracle database. For any database, there is at least one instance referencing the database.

For pre-release 8.1 databases, SID was used to identify the database. The SID was included in the part of the connect descriptor in a tnsnames.ora file, and in the definition of the listener in the listener.ora file.


An alternate name for the top directory in the Oracle directory hierarchy on some directory-based operating systems.


Open Systems Interconnection. See Open Systems Interconnection (OSI).

Oracle8i JServer

Provides support for Java stored procedures, JDBC, SQLJ, Common Object Request Broker Architecture (CORBA), and Enterprise JavaBeans (EJBs) in the Oracle8i database.



A block of information sent over the network each time a connection or data transfer is requested. The information contained in packets depends on the type of packet: connect, accept, redirect, data, etc. Packet information can be useful in troubleshooting.


Information passed to a program, command, or function, such as a file specification, a keyword, or a constant value.


A string (word or phrase) used for data security and known only to its owner. Passwords are entered in conjunction with an operating system login ID, Oracle username, or account name, in order to connect to an operating system or software application (such as the Oracle database). Whereas the username or ID is public, the secret password ensures that only the owner of the username can use that name, or access that data.

PMON process

A process monitor database process that performs process recovery when a user process fails. PMON is responsible for cleaning up the cache and freeing resources that the process was using. PMON also checks on dispatcher (see below) and server processes and restarts them if they have failed. As a part of service registration, PMON registers instance information with the listener.

preferred Oracle Names server

The Oracle Names server(s) preferred by a client for names resolution; usually the Oracle Names Server that is physically closest to the client, or available over the least expensive network link.

presentation layer

The presentation layer manages the representation of information that application layer entities either communicate or reference in their communication. Example of session layers are Two-Task Common (TTC) and General Inter-ORB Protocol (GIOP).

prespawned dedicated server

Prespawned dedicated server processes are prestarted by the listener before any incoming connection requests. They improve the time it takes to establish a connection on servers where multi-threaded server (MTS) is not used or not supported on a given machine. They also use allocated memory and system resources better by recycling server processes for use by other connections with shutting down and recreating a server.

private database link

A database link created by one user for his or her exclusive use.

See also database link, global database link, and public database link.


A collection of parameters that specifies preferences for enabling and configuring Net8 features on the client or server. A profile is stored and implemented through the sqlnet.ora file.

protocol address

An address that identifies the network address of a network object.

When a connection is made, the client and the receiver of the request, such as the listener, Oracle Names server or Oracle Connection Manager, are configured with identical protocol addresses. The client uses this address to send the connection request to a particular network object location, and the recipient "listens" for requests on this address. It is important to install the same protocols for the client and the connection recipient, as well as configure the same addresses.

protocol stack

Designates a particular presentation layer and session layer combination.

public database link

A database link created by a DBA on a local database which is accessible to all users on that database.

See also database link, global database link, and private database link.



Relational Database Management System


See Relative Distinguished Name (RDN) .

Relative Distinguished Name (RDN)

The local, most granular level entry name. It has no other qualifying entry names that would serve to uniquely address the entry. In the example, cn=sales,dc=us,dc=acme,dc=com, cn=sales is the RDN.


See administrative region.

region database

Tables in an Oracle database that store Oracle Names information.

root administrative region

The highest level administrative region in a distributed installation. The root administrative region contains the root domain.

root domain

The highest level domain in a hierarchical naming model.


Remote Procedure Call


Secure Sockets Layer (SSL)

An industry standard protocol designed by Netscape Communications Corporation for securing network connections. SSL provides authentication, encryption, and data integrity using public key infrastructure (PKI).

Sequenced Packet Exchange (SPX)

service handler

A service handler can be a multi-threaded server dispatcher, dedicated server, or prespawned dedicated server.

service registration

A feature by which the PMON process automatically registers information with a listener. Because this information is registered with the listener, the listener.ora file does not need to be configured with this static information.

Service registration provides the listener with the following information:

Service registration provides the listener with information about:

service replication

A process that fully replicates a directory system on the network. New services need to register with only one Names Server. The service replication process automatically distributes the new registration to all other active Names Servers on the network.

service name

A logical representation of a database, which is the way a database is presented to clients. A database can be presented as multiple services and a service can be implemented as multiple database instances. The service name is a string that is the global database name, a name comprised of the database name and domain name, entered during installation or database creation. If you are not sure what the global database name is, you can obtain it from the combined values of the SERVICE_NAMES parameter in the initialization parameter file.

The service name is included in the connect data part of the connect descriptor.

session layer

The session layer provides the services needed by the presentation layer entities that enable them to organize and synchronize their dialogue and manage their data exchange. This layer establishes, manages, and terminates network sessions between the client and server. An example of a session layer is Network Session (NS).


Oracle System Identifier. See Oracle System Identifier (SID).


A section of the listener.ora that defines the Oracle System Identifier (SID) of the database served by the listener. This section is only valid for version 7.x and version 8.0 Oracle databases, as release 8.1 instance information is now automatically registered with the listener. Static configuration is also required for other services, such as external procedures and heterogeneous services, and some management tools, including Oracle Enterprise Manager.

SPX protocol

Sequenced Packet Exchange protocol. A protocol known for high performance and acceptance among many major network management systems, in particular, Novell Advanced NetWare.


Net8's precursor. An Oracle product that works with the Oracle Server and enables two or more computers that run the Oracle RDBMS or Oracle tools such as SQL*Forms to exchange data through a network. SQL*Net supports distributed processing and distributed database capability. SQL*Net runs over and interconnects many communications protocols.

sqlnet.ora file

A configuration file for the client or server that specifies:

The sqlnet.ora file typically resides in $ORACLE_HOME/network/admin on UNIX platforms and ORACLE_HOME\network\admin on Windows platforms.


Secure Sockets Layer. See Secure Sockets Layer (SSL).

System Global Area (SGA)

A group of shared memory structures that contain data and control information for an Oracle instance.

system or topology data

Data used by the Oracle Names server to control regular functioning or communicate with other Oracle Names servers. Includes interchanges, root region's Oracle Names servers, and any delegated regions' Oracle Names servers.


TCP/IP protocol

Transmission Control Protocol/Internet Protocol. The de facto standard Ethernet protocol used for client/server conversation over a network.


TCP/IP with Secure Sockets Layer. A protocol that enables an Oracle application on a client to communicate with remote Oracle databases through TCP/IP and SSL (if the Oracle database is running on a host system that supports network communication using TCP/IP and SSL).

Thin JDBC Driver

Thin JDBC driver is Oracle's Type 4 driver designed for Java applet and Java application developers. The JDBC driver establishes a direct connection to the Oracle database server over Java sockets. Access to the database is assisted with a lightweight implementation of Net8 and Two-Task Common (TTC).


See Transparent Network Substrate (TNS).

tnsnames.ora file

A configuration file that contains net service name mapped to connect descriptors. This file is used for the local naming method. The tnsnames.ora file typically resides in $ORACLE_HOME/network/admin on UNIX platforms and ORACLE_HOME\network\admin.


A facility that writes detailed information about an operation to an output file. The trace facility produces a detailed sequence of statements that describe the events of an operation as they are executed. Administrators use the trace facility for diagnosing an abnormal condition; it is not normally turned on.

See also logging.

Transparent Application Failover (TAF)

A runtime failover for high-availability environments, such as Oracle Parallel Server and Oracle Fail Safe, that refers to the failover and re-establishment of application-to-service connections. It enables client applications to automatically reconnect to the database if the connection fails, and optionally resume a SELECT statement that was in progress. This reconnect happens automatically from within the Oracle Call Interface (OCI) library.

Transparent Network Substrate (TNS)

A foundation technology, built into Net8, Oracle Connection Manager and Oracle Names, that works with any standard network transport protocol.


A networking layer that maintains end-to-end reliability through data flow control and error recovery methods. Net8 uses Oracle Protocols for the transport layer.


Two-Task Common. See Two-Task Common (TTC) .

Two-Task Common (TTC)

TTC is a presentation layer type that is used in typical Net8 connection to provide character set and data type conversion between different character sets or formats on the client and server.


user name

The name by which a user is known to the Oracle Server and to other users. Every username is associated with a password, and both must be entered to connect to an Oracle database.


User Program Interface


virtual circuit

A piece of shared memory used by the dispatcher for client database connection requests and replies. The dispatcher places a virtual circuit on a common queue when a request arrives. An idle shared server picks up the virtual circuit from the common queue, services the request, and relinquishes the virtual circuit before attempting to retrieve another virtual circuit from the common queue.


well-known Oracle Names server

Addresses for one or more Oracle Names servers hardcoded into both the Oracle Names server and its clients. Oracle Names servers then become available at these well known addresses, so that clients do not need to be told, by way of configuration files, where to find the server.

Windows NT native authentication

An authentication method that enables a client single login access to a Windows NT server and a database running on the server.

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