Diff between update modes

Question

hi guru's
i have one doubt regarding lo extraction.
we have 3 types of update modes in lo extraction. those are
queued delta
direct delta
unserialized v3 update
when will u go for each delta mode
what are the advantages and disadvantages of each delta mode
plz reply me asap.
thank u
from
v.vijay

Answer 1

Hi,
Update Methods > Direct Delta, Queued, Non-serialized V3 Update and Serialized V3 (obsolete)
Direct Delta
Queued Delta
Un-serialized V3 Update
Serialized  V3 Update (obsolete)
Direct Delta (update mode A): With this update mode, the extraction data is transferred with each document posting directly into the BW delta queue. In doing so, each document posting with delta extraction is posted for exactly one LUW in the respective BW delta queues.
• Each document posting is directly transferred into the BW delta queue
• Each document posting with delta extraction leads to exactly one LUW in the respective BW delta queues
Transaction postings lead to:
1. Records in transaction tables and in update tables
2. A periodically scheduled job transfers these postings into the BW delta queue
3. This BW Delta queue is read when a delta load is executed.
Pros:
• Extraction is independent of V2 update
• Less monitoring overhead of update data or extraction queue
Cons:
• Not suitable for environments with high number of document changes
• Setup and delta initialization have to be executed successfully before document postings are resumed
• V1 is more heavily burdened
With this update mode, extraction data is transferred directly to the BW delta queues every time a document is posted. In this way, each document posted with delta extraction is converted to exactly one LUW in the related BW delta queues. If you are using this method, there is no need to schedule a job at regular intervals to transfer the data to the BW delta queues. On the other hand, the number of LUWs per DataSource increases significantly in the BW delta queues because the deltas of many documents are not summarized into one LUW in the BW delta queues as was previously the case for the V3 update.
If you are using this update mode, note that you cannot post any documents during delta initialization in an application from the start of the recompilation run in the OLTP until all delta init requests have been successfully updated successfully in BW. Otherwise, data from documents posted in the meantime is irretrievably lost. The restrictions and problems described in relation to the "Serialized V3 update" do not apply to this update method.
This update method is recommended for the following general criteria:
a) A maximum of 10,000 document changes (creating, changing or deleting documents) are accrued between two delta extractions for the application in question. A (considerably) larger number of LUWs in the BW delta queue can result in terminations during extraction.
b) With a future delta initialization, you can ensure that no documents are posted from the start of the recompilation run in R/3 until all delta-init requests have been successfully posted. This applies particularly if, for example, you want to include more organizational units such as another plant or sales organization in the extraction. Stopping the posting of documents always applies to the entire client.
Queued Delta: With this update mode, the extraction data is collected for the affected application instead of being collected in an extraction queue, and can be transferred as usual with the V3 update by means of an updating collective run into the BW delta queue. In doing so, up to 10000 delta extractions of documents for an LUW are compressed for each DataSource into the BW delta queue, depending on the application.
• Extraction data is collected for the affected application in an extraction queue
• Collective run as usual for transferring data into the BW delta queue
Transaction postings lead to:
1. Records in transaction tables and in extraction queue
2. A periodically scheduled job transfers these postings into the BW delta queue
3. This BW Delta queue is read when a delta load is executed.
Pros:
• Extraction is independent of V2 update
• Suitable for environments with high number of document changes
• Writing to extraction queue is within V1-update: this ensures correct serialization
• Downtime is reduced to running the setup
Cons:
• V1 is more heavily burdened compared to V3
• Administrative overhead of extraction queue
With this update mode, the extraction data for the affected application is compiled in an extraction queue (instead of in the update data) and can be transferred to the BW delta queues by an update collective run, as previously executed during the V3 update.
Up to 10,000 delta extractions of documents to an LUW in the BW delta queues are cumulated in this way per DataSource, depending on the application.
If you use this method, it is also necessary to schedule a job to regularly transfer the data to the BW delta queues ("update collective run"). However, you should note that reports delivered using the logistics extract structures Customizing cockpit are used during this scheduling. This scheduling is carried out with the same report which is used when you use the V3 updating (RMBWV311, RMBWV312 or RMBWV313).There is no point in scheduling with the RSM13005 report for this update method since this report only processes V3 update entries. The simplest way to perform scheduling is via the "Job control" function in the logistics extract structures Customizing Cockpit. We recommend that you schedule the job hourly during normal operation - that is, after successful delta initialization.
In the case of a delta initialization, the document postings of the affected application can be included again after successful execution of the recompilation run in the OLTP (e.g OLI7BW, OLI8BW or OLI9BW), provided that you make sure that the update collective run is not started before all delta Init requests have been successfully updated in the BW.
In the posting-free phase during the recompilation run in OLTP, you should execute the update collective run once (as before) to make sure that there are no old delta extraction data remaining in the extraction queues when you resume posting of documents.
Using transaction SMQ1 and the queue names MCEX11, MCEX12 or MCEX13 you can get an overview of the data in the extraction queues.
If you want to use the functions of the logistics extract structures Customizing cockpit to make changes to the extract structures of an application (for which you selected this update method), you should make absolutely sure that there is no data in the extraction queue before executing these changes in the affected systems. This applies in particular to the transfer of changes to a production system. You can perform a check when the V3 update is already in use in the respective target system using the RMCSBWCC check report.
In the following cases, the extraction queues should never contain any data:
- Importing an R/3 Support Package
- Performing an R/3 upgrade
For an overview of the data of all extraction queues of the logistics extract structures Customizing Cockpit, use transaction LBWQ. You may also obtain this overview via the "Log queue overview" function in the logistics extract structures Customizing cockpit. Only the extraction queues that currently contain extraction data are displayed in this case.
The restrictions and problems described in relation to the "Serialized V3 update" do not apply to this update method.
This update method is recommended for the following general criteria:
a) More than 10,000 document changes (creating, changing or deleting a document) are performed each day for the application in question.
b) In future delta initializations, you must reduce the posting-free phase to executing the recompilation run in R/3. The document postings should be included again when the delta Init requests are posted in BW. Of course, the conditions described above for the update collective run must be taken into account.
Un-serialized V3 Update: With this update mode, the extraction data for the application considered is written as before into the update tables with the help of a V3 update module. They are kept there as long as the data is selected through an updating collective run and are processed. However, in contrast to the current default settings (serialized V3 update), the data in the updating collective run are thereby read without regard to sequence from the update tables and are transferred to the BW delta queue.
• Extraction data for written as before into the update tables with a V3 update module
• V3 collective run transfers the data to BW Delta queue
• In contrast to serialized V3, the data in the updating collective run is without regard to sequence from the update tables
Transaction postings lead to:
1. Records in transaction tables and in update tables
2. A periodically scheduled job transfers these postings into the BW delta queue
3. This BW Delta queue is read when a delta load is executed.
Issues:
• Only suitable for data target design for which correct sequence of changes is not important e.g. Material Movements
• V2 update has to be successful
Note: Before PI Release 2002.1 the only update method available was V3 Update. As of PI 2002.1 three new update methods are available because the V3 update could lead to inconsistencies under certain circumstances. As of PI 2003.1 the old V3 update will not be supported anymore.
With this update mode, the extraction data of the application in question continues to be written to the update tables using a V3 update module and is retained there until the data is read and processed by a collective update run.
However, unlike the current default values (serialized V3 update); the data is read in the update collective run (without taking the sequence from the update tables into account) and then transferred to the BW delta queues.
The restrictions and problems described in relation to the "Serialized V3 update" do not apply to this update method since serialized data transfer is never the aim of this update method. However, you should note the following limitation of this update method:
The extraction data of a document posting, where update terminations occurred in the V2 update, can only be processed by the V3 update when the V2 update has been successfully posted.
This update method is recommended for the following general criteria:
a) Due to the design of the data targets in BW and for the particular application in question, it is irrelevant whether or not the extraction data is transferred to BW in exactly the same sequence in which the data was generated in R/3.
Serialized V3 (obsolete)
• Transaction data is collected in the R/3 update tables
• Data in the update tables is transferred through a periodic update process to BW Delta queue
• Delta loads from BW retrieve the data from this BW Delta queue
Transaction postings lead to:
1. Records in transaction tables and in update tables
2. A periodically scheduled job transfers these postings into the BW delta queue
3. This BW Delta queue is read when a delta load is executed.
Issues:
• Even though it says serialized, correct sequence of extraction data cannot be guaranteed
• V2 Update errors can lead to V3 updates never to be processed
Thanks,
JituK