SLT Replication - Delta

[Former Member]

Hi,

In case of SLT replication, how is delta replication handled? i.e. how is the newly created/changed records in the base tables identified & transfered?

Thanks in advance,

priya. 

[Former Member · Accepted solution]

Hi Priya,

After the intiial load is done into HANA, the database trigger in your source system will record any changes to source application tables into a logging table. The replication server will then facilitate the transfer these changes alone into the target (HANA). You can control the initial and replication load from Data Provisioning in HANA.

The document https://websmp204.sap-ag.de/~sapidb/011000358700000604912011 explains the architecture and the various modules/systems involved.

Thanks,

Anooj

[former_member182277 · Accepted solution]

Hello Priya,

This is depend on following factors:

1. While creatign schema under the  LTR transaction what mode of replication you are using:

Real time/interval/date

if you are using real time then at the moment you are creating a reocrd in the ECC system then the same reocr you are ablt to see in the SAP HANA.

For example:

I have created a new PO in ME21N transaction in ECC side

Copy the PO number.

Now, execute the query in the SAP HAAN:

select * from "<schema_name>"."EKKO" where EBELN = '<PO number>'

and you can realise then same record is reflected in SAP HANA.

Hope it is useful.

Regards,

neha

[Former Member · Accepted solution]

Thanks Anooj, do we have diff logging tables for each table like VBAP, BSEG or just one for all the R/3 tables put together?? is it based on timestamp or how is it? any more details?

Priya.

[Former Member · Accepted solution]

Hi Priya,

Yes, each table that you replicate will have separate logging tables automatically generated.

So in your LTR system, if you go into transaction IUUC_SYNC_MON and in the tab "Relevant Tables", if you give your Mass Transfer ID (this ID is unique to every source system schema that you configure in LTR - you can find your transfer ID using F4 help) and hit refresh, it will list out all tables that you have loaded or in the process of replicating. It also tells you the name of the logging table created for each of the tables you are replicating. You can go into these logging tables directly using SE16 in your source system.

Yes, logging tables will have a sequence and timestamp field, also the key fields of your corresponding replicating table and few other fields as well...  The following figure shows the logging table for the SAP table DD02T. The highlighted columns are the key fields of table DD02T and this will change based on the replication table you have selected.

When a change happens, the DB trigger module writes the table key that has changed along with other information into these logging tables.

At replication runtime, the read modules in the SLT system will refer to this loggin table to get the change information (key fields) since the last replication run and use that to read from the source application tables and subsequently passes it over to HANA (target system).

Hope that helps.

Thanks,

Anooj

[Former Member]

HI All,

What is meant by Delta replication?

[former_member313402]

Delta replication is where you capture the changes to to a table, its "deltas".  You don't just want the new rows, but the updates and deletes to existing rows too.  These need to get moved to the warehouse or datamart and applied. - Chirs