Compare classical migration with the SAP database migration option (DMO)
Classical migration
With the Classical Migration option, SAP’s Software Provisioning Manager (SWPM) is used as the Software Logistics (SL) tool and is exclusively for database migrations. SWPM exports data from a source system and imports it to a target system where the target can be any DB (SQL server, Oracle, DB2, etc.). This method in particular uses a file-based approach.
SAP database migration option (DMO)
DMO facilitates both an SAP upgrade and a database migration to the SAP HANA database via one tool. As both steps are handled at once, the DMO process is often referred to as a one-step migration. In comparison, Classical Migration uses a heterogenous system copy approach (thus garnering it the title of a two-step migration or "lift and shift" migration) with the first step being that of a migration followed by a second step facilitating an SAP upgrade.
Classical Migration vs DMO
Parameter
Classical migration
DMO
Purpose/Use case
Migration only
Upgrade + migration new DMO version available for migration-only option
Downtime optimization flexibility
High
Medium
Migration
Manual
Automated
Migration expertise
OS/DB certification is mandatory
OS/DB is not mandatory, but highly recommended
Data consistency
Manual
Automatic
Options for data transfer
Socket mode option Net exchange mode option FTP mode option to transfer data
Memory pipes filesystem dump
Migration check service
Migration check service required for classical approach on productive systems
No migration check service required for DMO on productive systems.
Monitoring progress
Distribution monitor and migration monitor tools available
Built-in SAPUI application for monitoring progress
Post-migration consistency check
Process is manual and requires MIGCHECK tool and the time analyzer tool to generate reports
Built-in feature in DMO
Table splitting
Dedicated table splitting and package splitting tools available – R3TA, R3ZCHECK
Table splitting is built-in and tuned
Import and Export Table Splitting
Table splitting for export and import can be changed on the fly
Table splitting and sorting requires adjustment as part of uptime (not on the fly)
DDL statements
Manual process to generate all DDL statements prior to migration
Built-in process for DDL statement calculations and deployment
SWPM, MIGMON, DISMON
SWPM, Migration Monitor (MIGMON) and Distribution Monitor (DISTMON) can be started and stopped manually Not recommended to run from remote desktops for MIGMON tools
No such option available in DMO No such restrictions in DMO
Export/import
Ability to add multiple application servers to run the export/import
Only one application server can be used
R3 load process limit
No limits
Limit of 999 R3 load processes
Table splits limit
No limit on number of table splits
Limit of 200 table splits
Target DB
anyDB (e.g. SAP HANA, SQL server, Oracle, DB2, etc.)
Only SAP HANA, AS (other databases are available upon request)
SAP recommendation
SAP recommended option if no software change is involved
SAP recommended option if SAP upgrade is in scope