Physical vs. Logical Migration
Streamlining data refresh processes
5-step-migration methodology

Physical vs. Logical Migration

As organizations are in constant change, IT structures must adapt regularly to address business reality. Among these processes data platform replacements are complex and risky projects generally undertaken only when absolutely necessary. Migration methods must be selected carefully to achieve project goals and minimize risks.

Physical Migration

To move data-bases between platforms with the same operating system and same Oracle version, physical migration is the usual solution of choice.


  • Can be executed with Oracle Data Guard (and RMAN) and minimum to zero downtime
  • Simple process
  • Minimum change in data-bases
  • Known procedure with DBAs

Limitations and disadvantages:

  • Defects and other problematics on source are also moved to target with no improvement of data
  • No data compression
  • Requires identical Oracle version on source and target
  • RMAN commands are applicable only for a limited number of platform combinations and same Endian combinations. For missing combinations, logical migration procedures must be applied (transportable table space/database or Data Pump import-expert).

In cases where data needs to be reorganized during physical migration, the process must follow the steps below:

  1. Upgrading the source (involving downtime and tests)
  2. Building Data Guard between sources and target
  3. Performing switch process – cut over, downtime and testing
  4. Data re-organization

Reorganizing and compressing data tend to be time-consuming processes that must be executed on the source, which is a live system. These procedures usually require additional downtime and can lead to poor performance or instability. Free space on the storage system is needed during the move.

Logical Migration

Logical migration is the solution of choice for any migration where different Oracle versions or operating systems are involved, as well as in cases when data is to be modified or improved during the process.


  • One down time for all changes, upgrades and reorganizations
  • No overhead: only required data is migrated
  • Requires only one tool
  • Handles migrations between different operating systems and Oracle versions


  • Complex process requiring expertise
  • Might be slow when multiple objects are involved
  • Complex process many DBAs aren’t familiar with

Methods for Logical Migration:

Export – ImportLong
Data PumpMedium
Insert/Select/ DB Link – ctas create tableShort
CSV filesLong

Built on the accumulated experience of senior DBAs, Accelario Migration Suite automates and accelerates logical migration, making it a low-risk process at the end of which organizations enjoy improved data quality and boosted performance of their IT systems.


Accelario solutions are based on the 5-step migration methodology we developed to automate and streamline data migration processes. Our methodology enables to move, refresh, consolidate and clone data bases in one phase, providing full control over the process and making script writing obsolete.

Accelario’s intuitive Management Interface walks users  through the process step by step:

1. Prepare prior to copy
Preparing database infrastructure on the target (users, tablespaces, compression types and more)

2. Copy data
Moving data with full control for users on both source and target sides.
Data from multiple sources (clone, physical server, production, test environments) can be copied in parallel; pace is set mainly by source power and size of tables.
As an advanced option, data moving can be combined with compression.

3. Create indexes
Simultaneous to copy process and performance monitoring: online configuration and property adaptation for maximum results

4. Copy views, procedures and sequences
Building views, procedures, sequences, etc. for all objects on the target

5. Compare and test
Compare source and target. The end user or application owner can start testing process. Run first back-up on target. Ready to build DR.

Accelario – Environment Refresh Manager (ERM ™ )

the business world as we know it today, requires fast and easy responses to changes. Organizations’ IT systems need to support such demands at any given time with minimum cost, effect or trouble to the ongoing business.
Almost any live business system today includes three or more different environments;

– Production – the live system where business need are 24 x7
– Development – where the next version is being developed
– Test – pre-testing the next version, must be as similar as possible to Production

Those needs require constant REFRESHMENT needs of the data, between Production and test environments in specific and to other environments as well, as per the organizations needs.

The need
One of the IT department services to the organization, including an on-going copy of data between Oracle databases (full database with scheme, specific table, only data, etc.). Move data or databases between cross platforms when Prod and Test are not identical. Activates and supports all software and hardware compression types. Performs the move of data with maximum speed and has a full control over the process, answering the organization and Dev department needs constantly.

The solution – Accelario ERM
Accelario ERM allows full control and on-going management of data move process on both sides – source and target.
ERM platform includes a unique possibility to combine 2 actions in one process – data move and data compression at the same time.

Use cases
While managing a production database, chances are high that you’ve had to clone your database to a different server other than the production server.
A cloned database is useful in a number of scenarios:

  • Troubleshoot your cloned production cluster in the safety of your test environment while performing destructive operations on the database.
  • Patch/upgrade test of a cloned database in order to validate the upgrade process before applying it to the production cluster.
  • Validate backup & recovery of a production cluster using a cloned cluster.
  • Validate or test new applications on a cloned production cluster before deploying it on the live production cluster.
  • Quickly clone the database for audit or information compliance requirements for example by quarter or year end where the content of the database must not be changed.
  • A reporting database can be created at intervals in order to avoid data changes during the report generations.
  • Migrate a database to new servers or a new data center.

Challenges depend on your environment profile, and include for example Cross platform copying, copying between difference oracle RDBMS versions, cloning a standard hardware and EXADATA or ZFS storage. More issues revolve around choosing the right copying method, minimizing the source downtime, configurating systems, forecasting storage accurately, taking advantage of all the new capabilities of the new software/hardware and testing required duplicate data is usually lengthy and expensive process.

Available Solutions
Oracle export / import procedures.
Oracle RMAN – along with Data Guard support a zero down time migration.
Self-development solution – based on scripts, usually done by the system DBA.
Transportable Database option – limited to source DB structure
Storage replication – limited to cases when you need to only copy data with no changes (same version same OS).

Refreshment Prerequisites – step by step

  1. Plan the process.
  2. Prepare source DB.
  3. Install Accelario Software on the both sides – source and target.
  4. Implement / deploy copying process.
  5. Check results.

Accelario ERM specialties
Performance is maximized.
Full online control over the copy process and Recover availability.
Cross platform support.
Ability to take advantage of all the new capabilities of oracle software and hardware – New Oracle software versions, advanced compression, partitions etc. EXADATA, ZFS, Hybrid Columnar Compression.
Minimal down time.

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