This topic is only relevant for the migration case.
Downtime-optimized conversion is based on moving downtime activities like migration (if relevant) and data conversion partially to uptime. Those tables, that are affected by the new data model and are undergoing a data conversion, have to be migrated first to the target SAP HANA database before they undergo the data conversion. Software Update Manager selects tables for migration in uptime automatically. However, it is possible to add additional tables to further reduce the amount of data, that has to be migrated during downtime.
Background for Table Selection
Downtime-optimized conversion migrates relevant application tables that are affected by conversion automatically in uptime. As mentioned, it is possible to manually add tables to uptime migration to further reduce downtime. The table names have to be provided to Software Update Manager in plain text file. There are different aspects that need to be considered:
- Table size is a reasonable as criterion, but migration duration is not always linear to table size.
- There are restrictions: some tables not selectable, like tables without primary key.
- Change rate is relevant: tables with high change rate shall not be selected, as replication may not be fast enough to work against change rate.
Software Update Manager Toolbox provides tool "Uptime table selection for downtime-optimized DMO" to cover these aspects.
Hint
Note
As soon as a logical table is listed in the file provided to Software Update Manager, Software Update Manager will automatically add all other related logical tables and the physical table.
| File name | Information |
|---|---|
| EUMIGRATEDTSIZES.LOG | Table sizes of tables migrated with R3load from a previous run. |
| MIGRATE_DT_DUR.XML | Migration duration and number of rows migrated from a previous run. |
| ZDIMPANA.ZIP | Table statistics (updates, inserts, deletes) from productive system |
| ALLTABU.DAT | Tables that receive import by R3trans. |
| DMOCRRTABLES.LST | Uptime tables from previous run (or previous tool usage) |
| EUMIGRATEOPTDMOSIZES.LOG | R3load table sizes from a previous downtime-optimized run. |
| MIGRATE_OPTDMO_INI_DUR.XML | Migration duration & number of rows migrated from a previous run. |
| NOXCONV.DAT | Tables that are not suitable (due to special table handling) |
| PUTTBX_S4T.ZIP | Static classification data for downtime-optimized Conversion |
| SFIN_TABLES.DMP | Information about dynamic SFIN tables not suitable (anyhow handled in uptime |
Note
In case you specify a table that is not allowed, Software Update Manager will throw an error. You will have to remove the table name from the cached Software Update Manager file, SUM/abap/mem/DMOCRRTABLES.LST, manually then.
The following screenshot shows you an example of what the result of the Uptime table selection for downtime-optimized DMO tool looks like. It's a table or grid listing table names, a green or red light indicating whether the table is suitable for uptime migration and other relevant information such as change rate. In addition, in the header an estimation is shown on how much migration time is moved to uptime with the active selection of tables.
As for Impact Analysis, it is possible to run the Uptime table selection for downtime-optimized DMO on a separate system with Software Update Manager Toolbox installed. Use the Export of SUM classification data tool to export static table classification in the PUTTBX_S4T.ZIP file from a conversion run with DMO from, for example, a sandbox (SBX) system. This file can be uploaded in another system.
Select Tables for Uptime Migration
In the following exercise, you will learn how to select the tables which you want to migrate in uptime.