Skip Headers
Oracle® Streams Concepts and Administration
11g Release 2 (11.2)

Part Number E17069-07
Go to Documentation Home
Home
Go to Book List
Book List
Go to Table of Contents
Contents
Go to Index
Index
Go to Master Index
Master Index
Go to Feedback page
Contact Us

Go to previous page
Previous
Go to next page
Next
PDF · Mobi · ePub
STRMS1284

Glossary

STRMS1285

action context

Optional information associated with a rule that is interpreted by the client of the rules engine when the rule is evaluated for a message.

STRMS1286

ANYDATA queue

A queue of type ANYDATA. These queues can stage messages of different types wrapped in an ANYDATA wrapper.

See Also: typed queue

STRMS1287

applied SCN

A system change number (SCN) relating to a capture process that corresponds to the most recent message dequeued by an apply process that applies changes captured by the capture process.

STRMS1288

apply forwarding

A directed network in which messages being forwarded at an intermediate database are first processed by an apply process. These messages are then recaptured by a capture process at the intermediate database and forwarded.

See Also: queue forwarding

STRMS1289

apply handler

A collection of SQL statements or a user-defined procedure used by an apply process for customized processing of messages. Apply handlers include statement DML handlers, message handlers, procedure DML handlers, DDL handlers, precommit handlers, and error handlers.

STRMS1290

apply process

An optional Oracle background process that dequeues messages from a specific queue and either applies each message directly, discards it, passes it as a parameter to an apply handler, or re-enqueues it. An apply process is an Oracle Streams client.

See Also: logical change record (LCR)

STRMS1291

apply servers

A component of an apply process that includes one or more processes that apply LCRs to database objects as DML or DDL statements or pass the LCRs to their appropriate apply handlers. For user messages, the apply servers pass the messages to the message handler. Apply servers can also enqueue logical change record (LCR) and non-LCR messages specified by the DBMS_APPLY_ADM.SET_ENQUEUE_DESTINATION procedure. If an apply server encounters an error, then it tries to resolve the error with a user-specified error handler. If an apply server cannot resolve an error, then it places the entire transaction, including all of its LCRs, in the error queue.

See Also: logical change record (LCR)

STRMS1292

apply user

The user in whose security domain an apply process dequeues messages that satisfy its rule sets, applies messages directly to database objects, runs custom rule-based transformations configured for apply process rules, and runs apply handlers configured for the apply process.

STRMS1293

approximate commit system change number (approximate CSCN)

An SCN value based on the current SCN of the database when a transaction that has enqueued messages into a commit-time queue is committed.

STRMS1294

archived-log downstream capture process

A downstream capture process that captures changes in archived redo log files copied from the source database to the downstream database.

STRMS1295

barrier transaction

A DDL transaction or a transaction that includes a row logical change record (row LCR) for which an apply process cannot identify the table rows or the database object by using the destination database data dictionary and virtual dependency definitions.

STRMS1297

buffered LCR

A logical change record (LCR) that is constructed explicitly by an application and enqueued into the buffered queue portion of an ANYDATA queue.

STRMS1298

buffered queue

The portion of a queue that uses the Oracle Streams pool to store messages in memory and a queue table to store messages that have spilled from memory.

STRMS1299

buffered user message

A non-LCR message of a user-defined type that is created explicitly by an application and enqueued into a buffered queue. A buffered user message can be enqueued into the buffered queue portion of an ANYDATA queue or a typed queue.

STRMS1296

builder server

A component of a capture process that is a process that merges redo records from the preparer server. These redo records either evaluated to TRUE during partial evaluation or partial evaluation was inconclusive for them. The builder server preserves the system change number (SCN) order of these redo records and passes the merged redo records to the capture process.

STRMS1690

capture database

The database running the capture process that captures changes made to the source database. The capture database and the source database are the same database when the capture process is a local capture process. The capture database and the source database are different when the capture process is a downstream capture process.

STRMS1300

capture process

An optional Oracle background process that scans the database redo log to capture DML and DDL changes made to database objects. A capture process is an Oracle Streams client.

STRMS1301

capture user

Either the user in whose security domain a capture process captures changes that satisfy its rule sets and runs custom rule-based transformations configured for capture process rules, or the user in whose security domain a synchronous capture captures changes that satisfy its rule set and runs custom rule-based transformations configured for synchronous capture rules.

STRMS1302

captured LCR

A logical change record (LCR) that was captured implicitly by a capture process and enqueued into the buffered queue portion of an ANYDATA queue.

See Also: user message

STRMS1303

captured SCN

The system change number (SCN) that corresponds to the most recent change scanned in the redo log by a capture process.

STRMS1304

change cycling

Sending a change back to the database where it originated. Typically, change cycling should be avoided in an information sharing environment by using tags and by using the LCR member function GET_SOURCE_DATABASE_NAME in rule conditions.

See Also: logical change record (LCR)

STRMS1610

change handler

A special type of statement DML handler that tracks table changes and was created by either the DBMS_STREAMS_ADM.MAINTAIN_CHANGE_TABLE procedure or the DBMS_APPLY_ADM.SET_CHANGE_HANDLER procedure.

STRMS1305

checkpoint

Information about the current state of a capture process that is stored persistently in the data dictionary of the database running the capture process.

STRMS1306

checkpoint interval

A regular interval at which a capture process attempts to record a checkpoint.

STRMS1307

checkpoint retention time

The amount of time that a capture process retains checkpoints before purging them automatically.

STRMS1308

column list

A list of columns for which an update conflict handler is called when an update conflict occurs for one or more of the columns in the list.

See Also: conflict resolution

STRMS1309

commit-time queue

A queue in which messages are ordered by their approximate commit system change number (approximate CSCN) values.

STRMS1310

conditional log group

A supplemental log group that logs the before images of all specified columns only if at least one of the columns in the supplemental log group is modified.

See Also: unconditional log group

STRMS1311

conflict

A mismatch between the old values in an LCR and the expected data in a table. Conflicts are detected by an apply process when it attempts to apply an LCR. Conflicts typically result when two different databases that are sharing data in a table modify the same row in the table at nearly the same time.

See Also: logical change record (LCR)

STRMS1312

conflict resolution

Handling a conflict to avoid an apply error. Either prebuilt update conflict handlers or custom conflict handlers can resolve conflicts.

STRMS1313

consumption

The process of dequeuing an message from a queue.

STRMS1314

coordinator process

A component of an apply process that is an Oracle background process that gets transactions from the reader server and passes them to apply servers.

STRMS1315

custom apply

An apply process passes an LCR as a parameter to a user procedure for processing. The user procedure can process the LCR in a customized way.

See Also: logical change record (LCR)

STRMS1316

custom rule-based transformation

A rule-based transformation that requires a user-defined PL/SQL function to perform the transformation.

See Also: declarative rule-based transformation

STRMS1317

database supplemental logging

The type of supplemental logging that can apply to the primary key, foreign key, and unique key columns in an entire database.

STRMS1318

DDL handler

An apply handler that uses a PL/SQL procedure to process DDL LCRs.

See Also: DDL logical change record (DDL LCR)

STRMS1319

DDL logical change record (DDL LCR)

A logical change record (LCR) that describes a data definition language (DDL) change.

STRMS1320

declarative rule-based transformation

A rule-based transformation that covers one of a common set of transformation scenarios for row LCRs. Declarative rule-based transformations are run internally without using PL/SQL.

See Also: row logical change record (row LCR) and custom rule-based transformation

STRMS1321

dequeue

To retrieve a message from a queue.

STRMS1322

destination database

A database where messages are consumed. Messages can be consumed when they are dequeued implicitly from a queue by a propagation or apply process, or messages can be consumed when they are dequeued explicitly by an application, a messaging client, or a user.

See Also: consumption

STRMS1323

destination queue

The queue that receives the messages propagated by a propagation from a source queue.

STRMS1324

direct apply

An apply process applies an LCR without running a user procedure.

See Also: logical change record (LCR)

STRMS1325

directed network

A network in which propagated messages pass through one or more intermediate databases before arriving at a destination database.

STRMS1550

DML handler

An apply handler that processes row LCRs.

See Also: row logical change record (row LCR)

STRMS1327

downstream capture process

A capture process that runs on a database other than its source database.

STRMS1328

downstream database

The database on which a downstream capture process runs.

STRMS1329

enqueue

To place a message in a queue.

STRMS1330

error handler

An apply handler that uses a PL/SQL procedure to try to resolve apply errors. An error handler is invoked only when a row logical change record (row LCR) raises an apply process error. Such an error might result from a conflict if no conflict handler is specified or if the update conflict handler cannot resolve the conflict.

STRMS1331

evaluation context

A database object that defines external data that can be referenced in rule conditions. The external data can exist as variables, table data, or both.

STRMS1332

exception queue

Messages are transferred to an exception queue if they cannot be retrieved and processed for some reason.

STRMS1333

explicit capture

The messages are enqueued into a queue by an application or a user.

STRMS1334

explicit consumption

The messages in a queue are dequeued either by a messaging client when it is invoked by a user or application or by an application or user directly.

STRMS1335

expression

A combination of one or more values and operators that evaluate to a value.

STRMS1336

file

In the context of a file group, a reference to a file stored on hard disk. A file is composed of a file name, a directory object, and a file type. The directory object references the directory in which the file is stored on hard disk.

STRMS1337

file group

A collection of versions.

STRMS1338

file group repository

A collection of all of the file groups in a database.

STRMS1339

first SCN

The lowest system change number (SCN) in the redo log from which a capture process can capture changes.

STRMS1340

global rule

A rule that is relevant either to an entire database or an entire queue.

STRMS1341

heterogeneous information sharing

Sharing information between Oracle and non-Oracle databases.

STRMS1342

high-watermark

The system change number (SCN) beyond which no messages have been applied by an apply process.

See Also: low-watermark

STRMS1343

ignore SCN

The system change number (SCN) specified for a table below which changes cannot be applied by an apply process.

STRMS1344

implicit capture

The messages are captured automatically by a capture process or by synchronous capture and enqueued into a queue.

STRMS1345

implicit consumption

The messages in a queue are dequeued automatically by an apply process.

STRMS1346

instantiation

The process of preparing database objects for instantiation at a source database, optionally copying the database objects from a source database to a destination database, and setting the instantiation SCN for each instantiated database object.

STRMS1347

instantiation SCN

The system change number (SCN) for a table which specifies that only changes that were committed after the SCN at the source database are applied by an apply process.

STRMS1348

LCR

See logical change record (LCR).

STRMS1349

LOB assembly

An option for DML handlers and error handlers that assembles multiple row LCRs resulting from a change to a single row with LOB columns into a single row LCR. LOB assembly simplifies processing of row LCRs with LOB columns in DML handlers and error handlers.

STRMS1350

local capture process

A capture process that runs on its source database.

STRMS1351

logical change record (LCR)

A message with a specific format that describes a database change.

See Also: row logical change record (row LCR) and DDL logical change record (DDL LCR)

STRMS1352

LogMiner data dictionary

A separate data dictionary used by a capture process to determine the details of a change that it is capturing. The LogMiner data dictionary is necessary because the primary data dictionary of the source database might not be synchronized with the redo data being scanned by a capture process.

STRMS1353

low-watermark

The system change number (SCN) up to which all messages have been applied by an apply process.

See Also: high-watermark

STRMS1354

maximum checkpoint SCN

The system change number (SCN) that corresponds to the last checkpoint interval recorded by a capture process.

STRMS1355

message

A unit of shared information in an Oracle Streams environment.

STRMS1356

message handler

An apply handler that uses a PL/SQL procedure to process persistent user messages.

See Also: logical change record (LCR)

STRMS1357

message rule

A rule that is relevant only for a user message of a specific message type.

STRMS1358

messaging client

An optional Oracle Streams client that dequeues persistent LCRs or persistent user messages when it is invoked by an application or a user.

STRMS1359

negative rule set

A rule set for an Oracle Streams client that results in the Oracle Streams client discarding a message when a rule in the rule set evaluates to TRUE for the message. The negative rule set for an Oracle Streams client always is evaluated before the positive rule set.

STRMS1360

nonpersistent queue

Nonpersistent queues store messages in memory. They are generally used to provide an asynchronous mechanism to send notifications to all users that are currently connected. Nonpersistent queues were deprecated in Oracle Database 10g Release 2. Oracle recommends that you use buffered messaging instead.

STRMS1361

nontransactional queue

A queue in which each message is its own transaction.

See Also: transactional queue

STRMS1362

object dependency

A virtual dependency definition that defines a parent-child relationship between two objects at a destination database.

STRMS1363

oldest SCN

For a running apply process, the earliest system change number (SCN) of the transactions currently being dequeued and applied. For a stopped apply process, the oldest SCN is the earliest SCN of the transactions that were being applied when the apply process was stopped.

STRMS1364

Oracle Streams client

A mechanism that performs work in an Oracle Streams environment and is a client of the rules engine (when the mechanism is associated with one or more rule sets). The following are Oracle Streams clients: capture process, propagation, apply process, and messaging client.

STRMS1365

Oracle Streams data dictionary

A separate data dictionary used by propagations and apply processes to keep track of the database objects from a particular source database.

STRMS1366

Oracle Streams pool

A portion of memory in the System Global Area (SGA) that is used by Oracle Streams. The Oracle Streams pool stores buffered queue messages in memory, and it provides memory for capture processes and apply processes.

STRMS1367

Oracle Streams topology

A representation of the databases in an Oracle Streams environment, the Oracle Streams components configured in these databases, and the flow of messages between these components.

STRMS1368

persistent LCR

A logical change record (LCR) that is enqueued into the persistent queue portion of an ANYDATA queue. A persistent LCR can be enqueued in one of the following ways:

STRMS1369

persistent queue

The portion of a queue that only stores messages on hard disk in a queue table, not in memory.

STRMS1370

persistent user message

A non-LCR message of a user-defined type that is enqueued into a persistent queue. A persistent user message can be enqueued in one of the following ways:

A persistent user message can be enqueued into the persistent queue portion of an ANYDATA queue or a typed queue.

STRMS1371

positive rule set

A rule set for an Oracle Streams client that results in the Oracle Streams client performing its task for a message when a rule in the rule set evaluates to TRUE for the message. The negative rule set for an Oracle Streams client always is evaluated before the positive rule set.

STRMS1372

precommit handler

An apply handler that can receive the commit information for a transaction and use a PL/SQL procedure to process the commit information in any customized way.

STRMS1373

prepared table

A table that has been prepared for instantiation.

STRMS1374

preparer server

A component of a capture process that scans a region defined by the reader server and performs prefiltering of changes found in the redo log. A reader server is a process, and multiple reader servers can run in parallel. Prefiltering entails sending partial information about changes, such as schema and object name for a change, to the rules engine for evaluation, and receiving the results of the evaluation.

STRMS1326

procedure DML handler

An apply handler that uses a PL/SQL procedure to process row LCRs.

See Also: row logical change record (row LCR)

STRMS1375

propagation

An optional Oracle Streams client that uses an Oracle Scheduler job to send messages from a source queue to a destination queue.

STRMS1376

propagation job

An Oracle Scheduler job used by a propagation to propagate messages.

STRMS1377

propagation schedule

A schedule that specifies how often a propagation job propagates messages.

STRMS1378

queue

The abstract storage unit used by a messaging system to store messages.

STRMS1379

queue forwarding

A directed network in which the messages being forwarded at an intermediate database are the messages received by the intermediate database, so that the source database for a message is the database where the message originated.

See Also: apply forwarding

STRMS1380

queue table

A database table where queues are stored. Each queue table contains a default exception queue.

STRMS1381

reader server

  1. A component of a capture process that is a process that reads the redo log and divides the redo log into regions.

  2. A component of an apply process that dequeues messages. The reader server is a process that computes dependencies between LCRs and assembles messages into transactions. The reader server then returns the assembled transactions to the coordinator process, which assigns them to idle apply servers.

See Also: logical change record (LCR)

STRMS1382

real-time downstream capture process

A downstream capture process that can capture changes made at the source database before the changes are archived in an archived redo log file.

STRMS1383

required checkpoint SCN

The system change number (SCN) that corresponds to the lowest checkpoint interval for which a capture process requires redo data.

STRMS1384

replication

The process of sharing database objects and data at multiple databases.

STRMS1385

resolution column

The column used to identify a prebuilt update conflict handler.

See Also: conflict resolution

STRMS1386

row logical change record (row LCR)

A logical change record (LCR) that describes a change to the data in a single row or a change to a single LONG, LONG RAW, or LOB column in a row that results from a data manipulation language (DML) statement or a piecewise operation. One DML statement can result in multiple row LCRs.

STRMS1387

row migration

An automatic conversion performed by an internal rule-based transformation when a subset rule evaluates to TRUE in which an UPDATE operation might be converted into an INSERT or DELETE operation.

STRMS1388

rule

A database object that enables a client to perform an action when an event occurs and a condition is satisfied.

STRMS1391

rule-based transformation

Any modification to a message when a rule in a positive rule set evaluates to TRUE.

STRMS1389

rule condition

A component of a rule which combines one or more expressions and conditions and returns a Boolean value, which is a value of TRUE, FALSE, or NULL (unknown).

STRMS1390

rule set

A group of rules.

STRMS1392

rules engine

A built-in part of Oracle that evaluates rule sets.

STRMS1393

schema rule

A rule that is relevant only to a particular schema.

STRMS1394

secure queue

A queue for which Oracle Streams Advanced Queuing (AQ) agents must be associated explicitly with one or more database users who can perform queue operations, such as enqueue and dequeue.

STRMS1395

source database

The database where changes captured by a capture process are generated in a redo log, or the database where a synchronous capture that generated LCRs is configured.

STRMS1396

source queue

The queue from which a propagation propagates messages to a destination queue.

STRMS1397

start SCN

The system change number (SCN) from which a capture process begins to capture changes.

STRMS1505

statement DML handler

An apply handler that uses one or more SQL statements to process row LCRs.

See Also: row logical change record (row LCR)

STRMS1398

subset rule

A rule that is relevant only to a subset of the rows in a particular table.

STRMS1399

supplemental log group

A group of columns in a table that is supplementally logged.

See Also: supplemental logging

STRMS1400

supplemental logging

Additional column data placed in a redo log whenever an operation is performed. A capture process captures this additional information and places it in LCRs, and the additional information might be needed for an apply process to apply LCRs properly at a destination database.

See Also: logical change record (LCR)

STRMS1401

synchronous capture

An optional Oracle Streams client that uses an internal mechanism to capture DML changes made to tables immediately after the changes are made.

STRMS1402

system-created rule

A rule with a system-generated name that was created using the DBMS_STREAMS_ADM package.

STRMS1403

table rule

A rule that is relevant only to a particular table.

STRMS1404

table supplemental logging

The type of supplemental logging that applies to columns in a particular table.

STRMS1405

tablespace repository

A collection of the tablespace sets in a file group.

STRMS1406

tag

Data of RAW data type that appears in each redo entry and LCR. You can use tags to modify the behavior of Oracle Streams clients and to track LCRs. Tags can also be used to prevent change cycling.

See Also: logical change record (LCR)

STRMS1407

topology

See Oracle Streams topology.

STRMS1506

transaction control directive

A special type of row LCR captured by a capture process or synchronous capture that contains transaction control statements, such as COMMIT and ROLLBACK.

See Also: row logical change record (row LCR)

STRMS1408

transactional queue

A queue in which messages can be grouped into a set that are applied as one transaction.

See Also: nontransactional queue

STRMS1409

typed queue

A queue that can stage messages of one specific type only.

See Also: ANYDATA queue

STRMS1410

unconditional log group

A supplemental log group that logs the before images of specified columns when the table is changed, regardless of whether the change affected any of the specified columns.

See Also: conditional log group

STRMS1411

user message

A non-LCR message of a user-defined type. A user message can be a buffered user message or a persistent user message.

See Also: logical change record (LCR)

STRMS1412

value dependency

A virtual dependency definition that defines a table constraint, such as a unique key, or a relationship between the columns of two or more tables.

STRMS1413

version

A collection of related files.

STRMS1414

virtual dependency definition

A description of a dependency that is used by an apply process to detect dependencies between transactions being applied at a destination database.

Reader Comment

   

Comments, corrections, and suggestions are forwarded to authors every week. By submitting, you confirm you agree to the terms and conditions. Use the OTN forums for product questions. For support or consulting, file a service request through My Oracle Support.

Hide Navigation

Quick Lookup

Database Library · Master Index · Master Glossary · Book List · Data Dictionary · SQL Keywords · Initialization Parameters · Advanced Search · Error Messages

Main Categories

This Page

This Document

New and changed documents:
RSS Feed HTML RSS Feed PDF