How shareplex works/ just little text about shareplex
How shareplex works/ just little text about shareplex the below content has been gather form shareplex documents Hope it helps for learners.
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How SharePlex works
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SharePlex replicates data using a set of replication processes; Capture, Read, Export, Import and post.
These processes start automatically, as they are needed, but they can be controlled with commands as well.
Let us discuss these processes to understand how SharePlex replication actually works.
Capture Process:
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The Capture process reads the redo logs or archive logs on the source systems for changes to objects.
Capture writes the data to the capture queue where it accumulates until the next SharePlex process is ready for it.
There is a separate Capture process for each data source being replicated.
Read Process:
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The Read process operates on the source system to read data from the capture queue and add routing information to the data;
after processing the data it sends it to the next queue. There is a separate Read process for each data source.
Export Process:
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The Export process operates on the source system to read data from the export queue and send it across the network to the target system.
By default, a source system has one Export process for each of its target systems. If there are two target systems, there are two Export processes.
Import Process:
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The Import process is the second half of the Export/Import transport pair, operating on the target system to receive data and build a post queue.
If there are two source systems replicating to a target system, there are two Import processes
Post Process: The Post process operates on the target system to read the
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post queue, construct SQL statements for replicated operations, and apply them to
target objects. There is a Post process for each post queue on a target system, and
multiple Post processes can operate simultaneously on a system.
SharePlex determines which transactions/objects to replicate based on the information provided in the configuration file.
SharePlex creates one or more messages that are sent from Capture to the Read process and from Read to all of the other replication processes in sequence.
A message can reflect a SQL operation like INSERT, UPDATE, DELETE, and COMMIT, TRUNCATE.
Large operations, like those on LONG or LOB columns, can require more than one message because a message has a size limitation.
Other operations, such as array inserts of small records, have the inverse effect: There could be one record for numerous operations.
For example, an array insert of 100,000 rows might be accommodated with only 1000 messages, depending on the data.
On the target system, the Post process receives the messages and constructs standard SQL statements to post replicated changes to the target database.
Much of this process is controlled by internal tables that were created during the installation of SharePlex.
The installation process of SharePlex on the source system and target system takes an hour or two and it is relatively simple. It is easy to administer and troubleshoot.
Customers looking for high-performance database replication for Oracle Database systems,
requiring support for thousands of rows per second for load distribution, disaster recovery,
migrations or for off-loading reporting should consider SharePlex for their mission critical database that support intensive transactions.
In Conclusion:
===============
This article discusses various Replication technologies.
IT managers need to plan how to use replication over the next several years before choosing a tool or developing their own tool using database features like streams.
Some factors to consider: How are replication needs expected to grow?
Is your company considering using replication for situations such as customer service, running reports or database testing or Disaster Recovery?
How often and how fast will you need to refresh the data in these alternate applications?
Do your users agree to long down times while you upgrade the database server or migrate to different platform?
This pick gathered from dell for the better ref
=====================================================================
How SharePlex works
=================================================
SharePlex replicates data using a set of replication processes; Capture, Read, Export, Import and post.
These processes start automatically, as they are needed, but they can be controlled with commands as well.
Let us discuss these processes to understand how SharePlex replication actually works.
Capture Process:
----------------
The Capture process reads the redo logs or archive logs on the source systems for changes to objects.
Capture writes the data to the capture queue where it accumulates until the next SharePlex process is ready for it.
There is a separate Capture process for each data source being replicated.
Read Process:
-----------
The Read process operates on the source system to read data from the capture queue and add routing information to the data;
after processing the data it sends it to the next queue. There is a separate Read process for each data source.
Export Process:
----------------
The Export process operates on the source system to read data from the export queue and send it across the network to the target system.
By default, a source system has one Export process for each of its target systems. If there are two target systems, there are two Export processes.
Import Process:
----------------
The Import process is the second half of the Export/Import transport pair, operating on the target system to receive data and build a post queue.
If there are two source systems replicating to a target system, there are two Import processes
Post Process: The Post process operates on the target system to read the
------------
post queue, construct SQL statements for replicated operations, and apply them to
target objects. There is a Post process for each post queue on a target system, and
multiple Post processes can operate simultaneously on a system.
SharePlex determines which transactions/objects to replicate based on the information provided in the configuration file.
SharePlex creates one or more messages that are sent from Capture to the Read process and from Read to all of the other replication processes in sequence.
A message can reflect a SQL operation like INSERT, UPDATE, DELETE, and COMMIT, TRUNCATE.
Large operations, like those on LONG or LOB columns, can require more than one message because a message has a size limitation.
Other operations, such as array inserts of small records, have the inverse effect: There could be one record for numerous operations.
For example, an array insert of 100,000 rows might be accommodated with only 1000 messages, depending on the data.
On the target system, the Post process receives the messages and constructs standard SQL statements to post replicated changes to the target database.
Much of this process is controlled by internal tables that were created during the installation of SharePlex.
The installation process of SharePlex on the source system and target system takes an hour or two and it is relatively simple. It is easy to administer and troubleshoot.
Customers looking for high-performance database replication for Oracle Database systems,
requiring support for thousands of rows per second for load distribution, disaster recovery,
migrations or for off-loading reporting should consider SharePlex for their mission critical database that support intensive transactions.
In Conclusion:
===============
This article discusses various Replication technologies.
IT managers need to plan how to use replication over the next several years before choosing a tool or developing their own tool using database features like streams.
Some factors to consider: How are replication needs expected to grow?
Is your company considering using replication for situations such as customer service, running reports or database testing or Disaster Recovery?
How often and how fast will you need to refresh the data in these alternate applications?
Do your users agree to long down times while you upgrade the database server or migrate to different platform?
This pick gathered from dell for the better ref
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