CHAPTER 1
Introduction to Oracle GoldenGate
第一章
Oracle GoldenGate简介
Oracle GoldenGate supported processing methods and databases
Oracle GoldenGate支持的处理方法和数据库
Oracle GoldenGate enables the exchange and manipulation of data at the transaction level
among multiple, heterogeneous platforms across the enterprise 1 . Its modular architecture
gives you the flexibility to extract and replicate selected data records, transactional
changes, and changes to DDL (data definition language 2 ) across a variety of topologies.
With this flexibility, and the filtering, transformation, and custom processing features of
Oracle GoldenGate, you can support numerous business requirements:
Oracle GoldenGate支持在事务级别交换和处理数据
跨企业的多个异构平台。其模块化架构使您可以灵活地提取和复制事务性所选数据记录
在多种拓扑之间进行更改以及对DDL(数据定义语言2)的更改。具有这种灵活性以及DDL(数据定义语言2)的过滤,转换和自定义处理功能
使用Oracle GoldenGate,您可以支持众多业务需求:
● Business continuance and high availability.
● 业务连续性和高可用
● Initial load and database migration.
● 初始化加载和数据迁移
● Data integration.
● 数据集成
● Decision support and data warehousing.
● 决策支持和数据仓库
Figure 1 Oracle GoldenGate supported topologies
图1 Oracle GoldenGate支持的拓扑
-
Support for replication across different database types and topologies varies by database type. See the Oracle GoldenGate Installation and Setup Guide for your database for detailed information about supported configurations.
对不同数据库类型和拓扑之间的复制的支持因数据库类型而异。有关支持的配置的详细信息,请参见数据库的《 Oracle GoldenGate安装和设置指南》
2. DDL is not supported for all databases
并非所有数据库都支持DDL
For full information about processing methodology, supported topologies and functionality, and configuration requirements, see
the Oracle GoldenGate Installation and Setup Guide for your database.
有关处理方法,支持的拓扑和功能以及配置要求的完整信息,请参见
适用于您的数据库的《 Oracle GoldenGate安装和设置指南》。
Supported only as a target database. Cannot be a source database for Oracle GoldenGate extraction.
** Uses a capture module that communicates with the Oracle GoldenGate API to send change data to Oracle GoldenGate.
*** Only like-to-like configuration is supported. Data manipulation, filtering, column mapping not supported.
仅支持作为目标数据库。不能是Oracle GoldenGate提取的源数据库。
**使用与Oracle GoldenGate API通信的捕获模块将更改数据发送到Oracle GoldenGate。
***仅支持类似的配置。不支持数据操作,过滤,列映射。
Overview of the Oracle GoldenGate architecture
Oracle GoldenGate 体系结构概述
可以出于以下目的配置Oracle GoldenGate
● 从一个数据库中静态提取数据记录并加载这些记录到另一个数据库
●连续提取和复制事务DML操作和DDL更改(对于受支持的数据库)以保持源数据和目标数据的一致性。
●从数据库中提取并复制到数据库外部的文件
Oracle GoldenGate由以下组件组成:
●Extract
● Data pump
● Replicat
● Trails or extract files
● Checkpoints
● Manager
● Collector
Figure 2 illustrates the logical architecture of Oracle GoldenGate for initial data loads and
for the synchronization of DML and DDL operations. This is the basic configuration.
Variations of this model are recommended depending on business needs.
图2 演示了Oracle GoldenGate用于初始数据加载以及DML和DDL操作同步的逻辑体系结构。这是基本配置。建议根据业务需要更改此模型。
Figure 2 Oracle GoldenGate logical architecture
图二 Oracle GoldenGate逻辑架构
Overview of Extract
The Extract process runs on the source system and is the extraction (capture) mechanism
of Oracle GoldenGate. You can configure Extract in one of the following ways:
● Initial loads: For initial data loads, Extract extracts (captures) a current, static set of
data directly from their source objects.
● Change synchronization: To keep source data synchronized with another set of data,
Extract captures DML and DDL operations after the initial synchronization has taken
place.
Extract captures from a data source that can be one of the following:
● Source tables, if the run is an initial load.
● The database recovery logs or transaction logs (such as the Oracle redo logs or SQL/MX
audit trails). The actual method of capturing from the logs varies depending on the
database type.
● A third-party capture module. This method provides a communication layer that
passes data and metadata from an external API to the Extract API. The database
vendor or a third-party vendor provides the components that extract the data
operations and pass them to Extract.
When configured for change synchronization, Extract captures the DML and DDL
operations that are performed on objects in the Extract configuration. Extract stores these
operations until it receives commit records or rollbacks for the transactions that contain
them. When a rollback is received, Extract discards the operations for that transaction.
When a commit is received, Extract persists the transaction to disk in a series of files called
a trail, where it is queued for propagation to the target system. All of the operations in each
transaction are written to the trail as a sequentially organized transaction unit. This
design ensures both speed and data integrity.
NOTE Extract ignores operations on objects that are not in the Extract configuration, even
though the same transaction may also include operations on objects that are in the
Extract configuration.
Multiple Extract processes can operate on different objects at the same time. For example,
two Extract processes can extract and transmit in parallel to two Replicat processes (with
two persistence trails) to minimize target latency when the databases are large. To
differentiate among different Extract processes, you assign each one a group name (see
“Overview of groups” on page 16).
Extract概述
抽取进程在源系统上运行,是Oracle GoldenGate的抽取(捕获)机制。可以通过以下方式之一配置提取:
● 初始加载:对于初始数据加载,直接从源对象中提取(捕获)当前静态数据集。
● 更改同步:为了使源数据与另一组数据同步,初始同步发生后,Extract捕获DML和DDL操作。
从以下数据源中抽取捕获:
●源表(如果运行是初始加载)。
●数据库恢复日志或事务日志(例如Oracle重做日志或SQL / MX审计跟踪)。从日志中捕获的实际方法取决于数据库类型。
●第三方捕获模块。此方法提供了一个通信层,该通信层将数据和元数据从外部API传递到Extract API。数据库供应商或第三方供应商提供提取数据操作并将其传递给Extract的组件。
为更改同步配置时,Extract捕获对Extract配置中的对象执行的DML和DDL操作。Extract存储这些操作,直到它接收到包含这些
操作的事务的提交记录或回滚。当接收到回滚时,Extract将放弃该事务的操作。 当接收到提交时,Extract将事务持久化到一系列
称为trail的文件中的磁盘,在这些文件中,事务排队等待传播到目标系统。每个事务中的所有操作都作为顺序组织的事务单元写入
trail。这个 设计确保速度和数据完整性。
注意即使同一事务可能还包括对在提取配置中的对象的操作,提取也将忽略不在提取配置中的对象的操作。
多个提取过程可以同时对不同的对象进行操作。例如,
两个提取过程可以并行提取和传输两个复制过程(两个持久性跟踪)当数据库很大时,将目标延迟最小化。要区分不同的提取过程,请为每个过程分配一个组名(请参阅第16页的“组概述”)。
Overview of data pumps
数据泵概述
A data pump is a secondary Extract group within the source Oracle GoldenGate
configuration. If a data pump is not used, Extract must send the captured data operations
to a remote trail on the target. In a typical configuration with a data pump, however, the
primary Extract group writes to a trail on the source system. The data pump reads this
trail and sends the data operations over the network to a remote trail on the target. The
data pump adds storage flexibility and also serves to isolate the primary Extract process
from TCP/IP activity.
数据泵是源端Oracle GoldenGate配置中的辅助抽取组
如果不使用数据泵,Extract必须将捕获的数据操作发送到目标上的远程跟踪,
然而,在典型的数据泵配置中 primary Extract group在源系统上写入跟踪。
数据泵读取此跟踪并将数据操作通过网络发送到目标上的远程跟踪。
数据泵增加了存储灵活性,还可以隔离主提取过程来自TCP / IP活动。
In general, a data pump can perform data filtering, mapping, and conversion, or it can be
configured in pass-through mode, where data is passively transferred as-is, without
manipulation. Pass-through mode increases the throughput of the data pump, because all
of the functionality that looks up object definitions is bypassed.
In most business cases, you should use a data pump. Some reasons for using a data pump
include the following:
通常,数据泵可以执行数据过滤,映射和转换,也可以配置为直通模式,在这种模式下,数据按原样被动传输,而无需进行操作。直通模式可提高数据泵的吞吐量,因为所有查找对象定义的功能中的一部分被绕过了。在大多数业务情况下,应使用数据泵。使用数据泵的一些原因包括以下这些:
● Protection against network and target failures: In a basic Oracle GoldenGate
configuration, with only a trail on the target system, there is nowhere on the source
system to store the data operations that Extract continuously extracts into memory. If
the network or the target system becomes unavailable, Extract could run out of
memory and abend. However, with a trail and data pump on the source system,
captured data can be moved to disk, preventing the abend of the primary Extract.
When connectivity is restored, the data pump captures the data from the source trail
and sends it to the target system(s).
●防止网络和目标故障:在基本的Oracle GoldenGate配置中,只有目标系统上的一条线索,源系统上没有任何地方可以存储连续提取到内存中的数据操作。如果网络或目标系统不可用,提取可能会耗尽内存和异常终止。但是,通过源系统上的trail和data pump,捕获的数据可以移动到磁盘,从而防止主提取的异常终止。当连接恢复时,data pump从源trail 捕获数据并将其发送到目标系统。
● You are implementing several phases of data filtering or transformation. When using
complex filtering or data transformation configurations, you can configure a data pump
to perform the first transformation either on the source system or on the target system,
or even on an intermediary system, and then use another data pump or the Replicat
group to perform the second transformation.
● 您正在实现数据过滤或转换的几个阶段。当使用复杂的过滤或数据转换配置时,可以配置数据泵
要在源系统或目标系统上执行第一个转换, 甚至在中间系统上,然后使用另一个数据泵或Replicat组执行第二次转换。
● Consolidating data from many sources to a central target. When synchronizing multiple
source databases with a central target database, you can store extracted data
operations on each source system and use data pumps on each of those systems to send
the data to a trail on the target system. Dividing the storage load between the source
and target systems reduces the need for massive amounts of space on the target system
to accommodate data arriving from multiple sources.
● 将来自许多来源的数据整合到一个中心目标。将多个源数据库与中央目标数据库同步时,可以在每个源系统上存储提取的数据操作,并在每个系统上使用数据泵进行发送数据到目标系统上的路径。在源系统和目标系统之间分配存储负载可以减少目标系统上需要大量空间来容纳来自多个源的数据。
● Synchronizing one source with multiple targets. When sending data to multiple target
systems, you can configure data pumps on the source system for each target. If network
connectivity to any of the targets fails, data can still be sent to the other targets.
● 同步一个源和多个目标。向多个目标系统发送数据时,可以在源系统上为每个目标配置数据泵。
如果到任何目标的网络连接失败,数据仍可以发送到其他目标
Overview of Replicat
复制概述
The Replicat process runs on the target system, reads the trail on that system, and then
reconstructs the DML or DDL operations and applies them to the target database. You can
configure Replicat in one of the following ways:
Replicat进程在目标系统上运行,读取该系统上的队列,然后重现DML或DDL操作并将其应用于目标数据库。
您可以通过以下方式之一配置Replicat:
● Initial loads: For initial data loads, Replicat can apply a static data copy to target objects
or route it to a high-speed bulk-load utility.
●初始加载:对于初始数据加载,Replicat可以将静态数据副本应用于目标对象或将其路由到高速大容量加载实用程序。
● Change synchronization: When configured for change synchronization, Replicat applies
the replicated source operations to the target objects using a native database interface
or ODBC, depending on the database type. To preserve data integrity, Replicat applies
the replicated operations in the same order as they were committed to the source
database.
●更改同步:当配置为更改同步时,Replicat使用本机数据库接口或ODBC将复制的源操作应用于目标对象,具体取决于数据库类型。为了保持数据完整性,Replicat按照提交给源数据库的相同顺序应用复制的操作。
You can use multiple Replicat processes with multiple Extract processes in parallel to
increase throughput. To preserve data integrity, each set of processes handles a different
set of objects. To differentiate among Replicat processes, you assign each one a group name
(see “Overview of groups” on page 16).
您可以将多个复制进程与多个提取进程并行使用,以提高吞吐量。为了保持数据完整性,每个进程集处理不同的对象集。为了区分复制进程,您为每个进程分配一个组名(参见第16页的“组概述”)。
You can delay Replicat so that it waits a specific amount of time before applying the
replicated operations to the target database. A delay may be desirable, for example, to
prevent the propagation of errant SQL, to control data arrival across different time zones,
or to allow time for other planned events to occur. The length of the delay is controlled by
the DEFERAPPLYINTERVAL parameter.
您可以延迟Replicat,以便它在将复制操作应用于目标数据库之前等待特定的时间量。延迟可能是可取的,例如,为了防止
错误的SQL的传播,为了控制跨不同时区的数据到达, 或者留出时间让其他计划的事件发生。延迟的长度由DEFERAPPLYINTERVAL
参数控制。
Overview of trails
队列概述
To support the continuous extraction and replication of database changes, Oracle
GoldenGate stores records of the captured changes temporarily on disk in a series of files
called a trail. A trail can exist on the source system, an intermediary system, the target
system, or any combination of those systems, depending on how you configure Oracle
GoldenGate. On the local system it is known as an extract trail (or local trail). On a remote
system it is known as a remote trail.
为了支持连续提取和复制数据库更改,Oracle GoldenGate将捕获的更改的记录临时存储在磁盘上称为trail的一系列文件中。路径可以存在于源系统,中间系统,目标系统或这些系统的任意组合,具体取决于您配置Oracle GoldenGate的方式。在本地系统上,它称为抽取路径(或本地路径)。在远程系统上,它称为远程路径。
By using a trail for storage, Oracle GoldenGate supports data accuracy and fault tolerance
(see “Overview of checkpoints” on page 14). The use of a trail also allows extraction and
replication activities to occur independently of each other. With these processes separated,
you have more choices for how data is processed and delivered. For example, instead of
extracting and replicating changes continuously, you could extract changes continuously
but store them in the trail for replication to the target later, whenever the target
application needs them.
通过使用trail队列进行存储,Oracle GoldenGate支持数据准确性和容错性 (见第14页“检查点概述”)。trail的使用
还允许提取和复制活动彼此独立地进行。有了这些分离的进程, 对于如何处理和传递数据,您有更多的选择。例如,您可
以连续抽取变化而将它们存储在trail中,而不是连续抽取和复制 ,以便以后在目标应用程序需要时复制到目标
Processes that write to, and read, a trail
写入和读取队列的进程
The primary Extract and the data-pump Extract write to a trail. Only one Extract process
can write to a trail, and each Extract must be linked to a trail.
主抽取和数据泵抽取写入队列。只有一个提取过程可以写入队列,并且每个提取必须链接到一个队列。
Processes that read the trail are:
读取队列的进程包括:
● Data-pump Extract: Extracts DML and DDL operations from a local trail that is linked
to a previous Extract (typically the primary Extract), performs further processing if
needed, and transfers the data to a trail that is read by the next Oracle GoldenGate
process downstream (typically Replicat, but could be another data pump if required).
●数据泵提取:从链接到上一个抽取(通常是主抽取)的本地队列中提取DML和DDL操作,如果需要,执行进一步的处理,并将数据传输到下一个Oracle GoldenGate进程下游读取的队列(通常是复制,但如果需要,可以是另一个数据泵)。
● Replicat: Reads the trail and applies replicated DML and DDL operations to the target
database.
● Replicat:读取队列并将复制的DML和DDL操作应用于目标数据库
Trail creation and maintenance
队列创建和维护
The trail files themselves are created as needed during processing, but you specify a two-
character name for the trail when you add it to the Oracle GoldenGate configuration with
the ADD RMTTRAIL or ADD EXTTRAIL command. By default, trails are stored in the dirdat sub-
directory of the Oracle GoldenGate directory.
队列文件本身是在进程中根据需要创建的,但是当使用以下方式将其添加到Oracle GoldenGate配置中时,可以为该队列指定一个两个字符的名称:ADD RMTTRAIL或ADD EXTTRAIL命令。缺省情况下,队列存储在Oracle GoldenGate目录的dirdat子目录中。
Full trail files are aged automatically to allow processing to continue without interruption
for file maintenance. As each new file is created, it inherits the two-character trail name
appended with a unique, six-digit sequence number from 000000 through 999999 (for
example c: \ggs\dirdat\tr000001 ). When the sequence number reaches 999999, the numbering
starts over at 000000.
完整的队列文件会自动老化,以便在不中断 文件维护中进程持续。在创建每个新文件时,它将继承两个字符的trail名称,
并附加一个从000000到999999的唯一六位序列号(例如c:\ ggs\dirdat\tr000001)。当序列号达到999999时 从000000
重新开始。
You can create more than one trail to separate the data from different objects or
applications. You link the objects that are specified in a TABLE or SEQUENCE parameter to a
trail that is specified with an EXTTRAIL or RMTTRAIL parameter in the Extract parameter file.
Aged trail files can be purged by using the Manager parameter PURGEOLDEXTRACTS .
To maximize throughput, and to minimize I/O load on the system, extracted data is sent
into and out of a trail in large blocks. Transactional order is preserved. By default, Oracle
GoldenGate writes data to the trail in canonical format, a proprietary format which allows
it to be exchanged rapidly and accurately among heterogeneous databases. However, data
can be written in other formats that are compatible with different applications.
For additional information about the trail and the records it contains, see Appendix 2 on
page 562.
您可以创建多条队列以将数据从不同的对象或应用程序中分离出来。将表或序列参数中指定的对象链接到提取参数文件中
使用EXTTRAIL或RMTTRAIL参数指定的轨迹。 可以使用管理器参数PURGEOLDEXTRACTS清除过时的队列文件。
为了最大化吞吐量和最小化系统上的I/O负载,提取的数据以大数据块的形式发送到和发送出一条路径。事务顺序被保留。
默认情况下, Oracle GoldenGate以规范格式将数据写入trail,这是一种专有格式,允许在异构数据库之间快速、准确地交
换数据。但是,数据 可以用与不同应用程序兼容的其他格式编写。 有关跟踪及其包含的记录的更多信息,请参阅第562页的
附录2。
Overview of extract files
抽取文件概述
In some configurations, Oracle GoldenGate stores extracted data in an extract file instead
of a trail. The extract file can be a single file, or it can be configured to roll over into
multiple files in anticipation of limitations on file size that are imposed by the operating
system. In this sense, it is similar to a trail, except that checkpoints are not recorded. The
file or files are created automatically during the run. The same versioning features that
apply to trails also apply to extract files.
在某些配置中,Oracle GoldenGate将提取的数据存储在抽取文件中而不是队列中。提取文件可以是单个文件,也可以
配置为在预期操作系统会限制文件大小的情况下滚动成多个文件。从这个意义上讲,它类似于队列,不同之处在于不记录
检查点。一个或多个文件在运行期间自动创建。适用于队列的相同版本控制功能也适用于提取文件。
Overview of checkpoints
检查点概述
Checkpoints store the current read and write positions of a process to disk for recovery
purposes. Checkpoints ensure that data changes that are marked for synchronization
actually are captured by Extract and applied to the target by Replicat, and they prevent
redundant processing. They provide fault tolerance by preventing the loss of data should
the system, the network, or an Oracle GoldenGate process need to be restarted. For
complex synchronization configurations, checkpoints enable multiple Extract or Replicat
processes to read from the same set of trails.
Checkpoints work with inter-process acknowledgments to prevent messages from being
lost in the network. Oracle GoldenGate has a proprietary guaranteed-message delivery
technology.
检查点将进程的当前读写位置存储到磁盘以进行恢复目的。检查点确保标记为同步的数据更改
实际上是由Extract捕获的,并由Replicat应用于目标的,它们可以防止冗余处理。它们通过防
止数据丢失来提供容错能力。系统,网络或Oracle GoldenGate进程需要重新启动。对于
复杂的同步配置,检查点可启用多个取抽或复制从同一组记录读取的过程。检查点与进程间确认
一起使用,以防止消息被发送迷失在网络中。 Oracle GoldenGate具有专有的保证消息交付技术。
Extract creates checkpoints for its positions in the data source and in the trail. Because
Extract only captures committed transactions, it must keep track of operations in all open
transactions, in the event that any of them are committed. This requires Extract to record
a checkpoint where it is currently reading in a transaction log, plus the position of the start
of the oldest open transaction, which can be in the current or any preceding log.
Extract为其在数据源和队列中的位置创建检查点。因为 Extract只捕获提交的事务,它必须跟踪所有打开的操作
事务,如果其中任何一个已提交。这需要摘录来记录 当前在事务日志中读取的检查点,加上开始位置 最早的打开
事务,可以在当前日志或任何前面的日志中。
To control the amount of transaction log that must be re-processed after an outage, Extract
persists the current state and data of processing to disk at specific intervals, including the
state and data (if any) of long-running transactions. If Extract stops after one of these
intervals, it can recover from a position within the previous interval or at the last
checkpoint, instead of having to return to the log position where the oldest open long-
running transaction first appeared. For more information, see the BR parameter in the
Oracle GoldenGate Windows and UNIX Reference Guide.
要控制中断后必须重新处理的事务日志量,请抽取 以特定的间隔将当前处理状态和数据持久化到磁盘,包括
长期运行事务的状态和数据(如果有)。如果提取在其中一个之后停止 间隔,它可以从上一个间隔或最后一个
间隔内的位置恢复 检查点,而不必返回到最早打开long的日志位置- 首次出现运行事务。有关详细信息,请参见
《Oracle GoldenGate Windows和UNIX参考指南》。
Replicat creates checkpoints for its position in the trail. Replicat stores its checkpoints in
a checkpoint table in the target database to couple the commit of its transaction with its
position in the trail file. The checkpoint table guarantees consistency after a database
recovery by ensuring that a transaction will only be applied once, even if there is a failure
of the Replicat process or the database process. For reporting purposes, Replicat also has
a checkpoint file on disk in the dirchk sub-directory of the Oracle GoldenGate directory.
Replicat为它在trail中的位置创建检查点。Replicat将其检查点存储在 目标数据库中的检查点表,用于将其
事务的提交与 在轨迹文件中的位置。检查点表保证数据库之后的一致性 通过确保事务只应用一次(即使出现
故障)来恢复 复制进程或数据库进程的。出于报告的目的,Replicat还有 磁盘上Oracle GoldenGate目录的
dirchk子目录中的检查点文件。
Checkpoints are not required for non-continuous types of configurations that can be re-run
from a start point if needed, such as initial loads.
对于可以重新运行的非连续类型的配置,不需要检查点 如果需要,从起点开始,例如初始负载。
Overview of Manager
manager概述
Manager is the control process of Oracle GoldenGate. Manager must be running on each
system in the Oracle GoldenGate configuration before Extract or Replicat can be started,
and Manager must remain running while those processes are running so that resource
management functions are performed. Manager performs the following functions:
Manager是Oracle GoldenGate的控制过程。必须在Oracle GoldenGate配置中的每个系统上运行管理器,然后才能
启动提取或复制, 当这些进程运行时,管理器必须保持运行,以便 执行管理功能。管理器执行以下功能:
● Start Oracle GoldenGate processes
● Start dynamic processes
● Maintain port numbers for processes
● Perform trail management
● Create event, error, and threshold reports
One Manager process can control many Extract or Replicat processes. On Windows
systems, Manager can run as a service. For more information about the Manager process
and configuring TCP/IP connections, see Chapter 3.
一个管理器进程可以控制多个提取或复制进程。在Windows系统上,Manager可以作为服务运行。有关管理器进程和配置TCP/IP连接的更多信息,请参阅第3章。
Overview of Collector
Collector概述
Collector is a process that runs in the background on the target system when continuous,
online change synchronization is active. Collector does the following:
收集器是一个进程,当连续的联机更改同步处于活动状态时,该进程在目标系统的后台运行。收集器执行以下操作:
● Upon a connection request from a remote Extract to Manger, scan and bind to an
available port and then send the port number to Manager for assignment to the requesting Extract process.
●从远程提取到管理器的连接请求后,扫描并绑定到可用端口,然后将端口号发送给管理器,以便分配到请求提取过程。
● Receive extracted database changes that are sent by Extract and write them to a trail
file. Manager starts Collector automatically when a network connection is required, so
Oracle GoldenGate users do not interact with it. Collector can receive information from
only one Extract process, so there is one Collector for each Extract that you use.
Collector terminates when the associated Extract process terminates.
接收通过提取发送的提取数据库更改,并将其写入跟踪文件。当需要网络连接时,Manager会自动启动收集器,因此
Oracle GoldenGate用户不会与其交互。收集器可以从仅 一个抽取过程进程接收信息,因此您使用的每个提取都有一个
收集器。 当关联的提取进程终止时,收集器终止。
NOTE Collector can be run manually, if needed. This is known as a static Collector (as
opposed to the regular, dynamic Collector). Several Extract processes can share
one static Collector; however, a one-to-one ratio is optimal. A static Collector can
be used to ensure that the process runs on a specific port. For more information
about the static Collector, see the Oracle GoldenGate Windows and UNIX
Reference Guide. For more information about how Manager assigns ports, see
Chapter 3.
如果需要,可以手动运行便笺收集器。这称为静态收集器(与常规的动态收集器相反)。
多个提取进程可以共享一个静态收集器;但是,一对一的比率是最佳的。静电收集器
用于确保进程在特定端口上运行。有关静态收集器的详细信息,请参阅《Oracle GoldenGate Windows和UNIX参考指南》。有关Manager如何分配端口的详细信息,请参阅
第三章。
By default, Extract initiates TCP/IP connections from the source system to Collector on the
target, but Oracle GoldenGate can be configured so that Collector initiates connections
from the target. Initiating connections from the target might be required if, for example,
the target is in a trusted network zone, but the source is in a less trusted zone. For
information about this configuration, see page 136.
默认情况下,“提取”会启动从源系统到目标上收集器的TCP/IP连接,但可以配置Oracle GoldenGate,以便收集器从
目标启动连接。可能需要从目标启动连接,例如, 目标位于受信任的网络区域,但源位于不受信任的区域。为了 有关此
配置的信息,请参阅第136页。
Overview of process types
进程类型概述
Depending on the requirement, Oracle GoldenGate can be configured with the following processing types.
根据需要,Oracle GoldenGate可以配置以下处理类型。
● An online Extract or Replicat process runs until stopped by a user. Online processes
maintain recovery checkpoints in the trail so that processing can resume after
interruptions. You use online processes to continuously extract and replicate DML and
DDL operations (where supported) to keep source and target objects synchronized. The
EXTRACT and REPLICAT parameters apply to this process type.
● A source-is-table Extract process extracts a current set of static data directly from the
source objects in preparation for an initial load to another database. This process type
does not use checkpoints. The SOURCEISTABLE parameter applies to this process type.
● A special-run Replicat process applies data within known begin and end points. You
use a special Replicat run for initial data loads, and it also can be used with an online
Extract to apply data changes from the trail in batches, such as once a day rather than
continuously. This process type does not maintain checkpoints, because the run can be
started over with the same begin and end points. The SPECIALRUN parameter applies to
this process type.
● A remote task is a special type of initial-load process in which Extract communicates
directly with Replicat over TCP/IP. Neither a Collector process nor temporary disk
storage in a trail or file is used. The task is defined in the Extract parameter file with
the RMTTASK parameter.
●在线提取或复制过程一直运行到用户停止为止。联机进程在跟踪中维护恢复检查点,以便在中断后恢复处理。您可以使用联机过程连续提取和复制DML和
DDL操作(如果支持)以保持源对象和目标对象同步。EXTRACT和REPLICAT参数应用于此进程类型。
●source-is-table提取过程直接从源对象中提取一组当前静态数据,以准备初始加载到另一个数据库。此进程类型不使用检查点。SOURCEISTABLE参数应用于此进程类型。
●特殊运行复制过程在已知起点和终点内应用数据。您可以使用一个特殊的Replicat run来加载初始数据,它还可以与一个联机提取一起使用,以成批应用来自trail的数据更改,
例如每天一次,而不是 连续不断地。此进程类型不维护检查点,因为可以使用相同的起点和终点重新开始运行。SPECIALRUN参数适用于此进程类型。
●远程任务是一种特殊类型的初始加载过程,其中Extract与 直接通过TCP/IP复制。不使用收集器进程或跟踪或文件中的临时磁盘存储。任务在提取参数文件中用RMTTASK参数定义。
Overview of groups
groups概述
To differentiate among multiple Extract or Replicat processes on a system, you define
processing groups. For example, to replicate different sets of data in parallel, you would
create two Replicat groups.
要区分系统上的多个提取或复制进程,请定义处理组。例如,要并行复制不同的数据集,可以创建两个复制组。
A processing group consists of a process (either Extract or Replicat), its parameter file, its
checkpoint file, and any other files associated with the process. For Replicat, a group also
includes the associated checkpoint table.
一个进程组由进程(Extract或Replicat)、其参数文件、检查点文件和与该进程关联的任何其他文件组成。对于Replicat,组还包含关联的检查点表。
You define groups by using the ADD EXTRACT and ADD REPLICAT commands in the Oracle
GoldenGate command interface, GGSCI. For permissible group names, see those
commands in the Oracle GoldenGate Windows and UNIX Reference Guide.
您可以使用OracleGoldenGate命令界面中的ADD EXTRACT和ADD REPLICAT命令来定义组。有关允许的组名,请参阅《Oracle GoldenGate Windows和UNIX参考指南》中的这些命令。
All files and checkpoints relating to a group share the name that is assigned to the group
itself. Any time that you issue a command to control or view processing, you supply a group
name or multiple group names by means of a wildcard.
与组相关的所有文件和检查点共享分配给组本身的名称。在发出控制或查看处理的命令时,可以通过通配符提供组名或多个组名
Overview of the Commit Sequence Number (CSN)
提交序列号(CSN)概述
使用Oracle GoldenGate时,可能需要引用提交序列号或CSN。CSN是Oracle GoldenGate为维护事务一致性和数据完整性而
构造的用于标识事务的标识符。 它 唯 一标识事务提交到数据库的时间点。 可以要求CSN在事务日志中定位Extract,以重新定位
Replicat 在队列上,或为了其他目的。它由一些转换函数返回,并且 包括在报告和某些GGSCI输出中。 有关CSN和每个数据库的
CSN值列表的更多信息,请参见附录 第559页。