Diffrence between Direct Delta,Que Delta and Un searlised v3 update

Question

Dear All,
Can any one explain the diffrence between Direct Delta,Que Delta and Un searlised v3 update and in which situation to which update mode.
Thanks in advance

Answer 1

Dear Friend,
Transaction posting lead to:
1. Records in transaction tables
2. For an initial load a setup needs to be executed which reads the transaction data and stores the data in a setup table
3. These setup tables are read during an initial or full load
4. Further transactions are posted into the transaction tables and also caught into Update tables / Extraction Queue.
5. A periodically scheduled job transfers these postings into the BW delta queue
6. This BW Delta queue is read when a delta load is executed.
a. Update methods: (serialized) V3
u2022 Transaction data is collected in the R/3 update tables
u2022 Data in the update tables is transferred through a periodic update process to BW Delta queue
u2022 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:
u2022 Even though it says serialized , Correct sequence of extraction data cannot be guaranteed
u2022 V2 Update errors can lead to V3 updates never to be processed
u2022 Details in SAP Note 505700
b. Update methods: direct delta
u2022 Each document posting is directly transferred into the BW delta queue
u2022 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:
u2022 Extraction is independent of V2 update
u2022 Less monitoring overhead of update data or extraction queue
Cons:
u2022 Not suitable for environments with high number of document changes
u2022 Setup and delta initialization have to be executed successfully before document postings are resumed
u2022 V1 is more heavily burdened
Note: Con 2: a delta queue has to present to collect the document postings. This queue is only available after a successful delta initialization.
c. Update methods: queued delta
u2022 Extraction data is collected for the affected application in an extraction queue
u2022 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:
u2022 Extraction is independent of V2 update
u2022 Suitable for environments with high number of document changes
u2022 Writing to extraction queue is within V1-update: this ensures correct serialization
u2022 Downtime is reduced to running the setup
Cons:
u2022 V1 is more heavily burdened compared to V3
u2022 Administrative overhead of extraction queue
d. Update methods: Un-serialized V3
u2022 Extraction data for written as before into the update tables with a V3 update module
u2022 V3 collective run transfers the data to BW Delta queue
u2022 In contrast to serialized V3, the data in the updating collective run is without regard to sequence from the update tables
Note: i. Pro 2: In doing so, up to 10000 delta extractions of documents for an LUW are compressed for each Data Source into the BW delta queue, depending on the application.
ii. Pro 4: Even without a successful initial load and thus no BW delta queue yet available, document postings are already collected in the extraction 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:
u2022 Only suitable for data target design for which correct sequence of changes is not important e.g. Material Movements
u2022 V2 update has to be successful
Hope this will be helpful.
Please respond back if there is still any query.
Varun