Oracle Network Administration - Glossary

Advanced Queuing

A pre-defined package enabling you to store messages into queues for deferred retrieval and processing by the Oracle server.

Advanced Queuing (AQ)

A utility to store transactions in a queue, distribute the queue to other databases, and then retrieve and run the queued transactions.

Break-Reset Connection:

A function in Oracle Net Services that allows a client to interrupt or terminate an existing connection to the database server. This might be necessary in situations where a session has become unresponsive or needs to be forcibly closed.

Cache fusion

A diskless data transfer method for Oracle Parallel Server (OPS) that moves information from the cache of one database instance to the cache of another database instance.

Connection load balancing

A feature of Oracle Network Services that reviews the load on each of a group of database services or database dispatchers, and then selects the least busy available service or dispatcher and assigns a new connection to it. Oracle RAC leverages connection load balancing to distribute client connection requests across the available instances in the cluster.

Connection Manager

A service that can be run along with Oracle Network Services to control multiple connections going to a Oracle Shared Server.

Connection Pooling

A feature of Multi-Threaded Server in which idle user connections are re-used temporarily, allowing more concurrent users to reach the database.

Deployment template

A set of commands that create one or more snapshots at a remote site. The template can be used repeatedly to create identify sets of snapshots at multiple remote sites.

Disk affinity

A database instance of an Oracle Parallel System has disk affinity with a data file when the data file is located on a disk that is mounted on the same computer as the database instance.

Equipartitioned table

A partitioned table that has an index that is also partitioned in exactly the same way as the table.

Failover

In the context of Oracle Net Services and high availability configurations, failover refers to the automatic switching of an application or client connection to a redundant database instance or service when the primary instance becomes unavailable. Oracle features like Application Continuity (AC) and Transparent Application Continuity (TAC) are designed to facilitate seamless failover.

getOracleArray

The getOracleArray method is an Oracle-specific extension that is not specified in the standard Array interface. The getOracleArray method retrieves the element values of the array into a Datum[] array. The elements are of the oracle.sql.* data type corresponding to the SQL type of the data in the original array. For an array of structured objects, this method will use oracle.sql.STRUCT instances for the elements. Oracle also provides a getOracleArray(index,count) method to get a subset of the array elements.

Hostname Resolution

The process by which a hostname (a human-readable name for a computer on a network) is translated into its corresponding IP address. Oracle Net Services relies on hostname resolution to establish connections between clients and database servers. This can be done through local host files or a Domain Name System (DNS) server.

Index-organized table

An Index-Organized Table (IOT) in Oracle is a type of table where the data is physically stored in index order, meaning the table *is* the index. This contrasts with traditional heap-organized tables where data and index are separate structures, and it's not directly related to Oracle Network Services, which focuses on enabling communication between Oracle database components and external applications across a network.

Instance affinity

A feature of DBMS_JOB package that limits a job in OPS to one database instance.

Instantiate

To create a specific version of an object (such as a snapshot) based on a template and some specific variables.

Jumbo Frames

Ethernet frames with a payload exceeding the standard Maximum Transmission Unit (MTU) of 1500 bytes. Using jumbo frames can improve network efficiency by reducing the number of frames that need to be processed, leading to lower CPU overhead and potentially higher throughput in environments where all devices support them.

MAP MEMBER function

A function defined as part of an object type to sort or compare object rows with one another.

Multimaster replication

Advanced replication features allowing updates on tables in remote sites as if every site were the master site.

Multiplexing

Combining several individual transmissions and sending them across a single connection to and from a database.

Node affinity

A database instance of an Oracle Parallel System has node affinity with a data file when the data file and the database instance are located on the same computer (also called the node).

Offline instantiation

Creating snapshot templates using export and import utilities. No connection is required between the master and the remote site during the process.

Online instantiation

Creating snapshot templates in real time with a connection between the master and the remote sites.

Oracle Parallel Server

A database server consisting of multiple database instances that act as a single database. The OPS distributes activity by concurrently executing transactions on multiple database instances. Each database instance can be located on a different machine to maximize use of resources.

Parallel queries

Queries are divided into smaller sections, and each section of the query executes simultaneously (in parallel) in the database server. This is not the same as Oracle Parallel Server.

Partitioned table

A table containing data in multiple physical tables. This divides large amounts of data into smaller segments.

Partitioning

Dividing one table into several sections, or partitions, which are physically stored as if each partition were a separate table.

Primary key snapshot

A copy of a table or view. Changed rows are refreshed by retrieving the row using its primary key value.

RADIUS

Acronym for Remote Authentication Dial-In User Service, a client-server security protocol that is used primarily with the Internet.

Real Application Clusters (RAC)

Oracle Real Application Clusters (RAC) leverages Oracle Network Services to enable multiple database instances running on separate servers to access and modify a shared set of datafiles. This network infrastructure facilitates the crucial inter-instance communication required for Cache Fusion and maintaining data consistency across the cluster. 

Row movement

The automatic shifting of a row from one partition to another when the value of the partitioning column in the row changes so that the row belongs in a different partition.

ROWID snapshot

A copy of a table. Changed rows are refreshed by retrieving the row using its ROWID.

Snapshot

A replica of a table or part of a table that resides on another database instance. Snapshots can be read-only or updateable.

Super administrator

In Oracle Enterprise Manager, a user with full privileges on the OEM console.

Transparent application failover (TAF)

A feature in Network Services to seamlessly move a user’s session from one instance to another when the original instance fails.

Trusted

A security model in which an administrator has access privileges to local and remote sites.

Untrusted

A security model in which an administrator has access privileges only to the local site.

Updateable snapshot

A snapshot that supports insert, update, and delete on the remote site.