# Migration options
<a name="migration-options"></a>

The following decision tree diagram presents the options as different migration paths based on the platform family, outage requirements, and configuration. These paths can help you understand different options:
+ Little endian compared with big endian
+ A short outage window (less than 15 minutes, with time unrelated to database size) compared with a long outage window (more than 15 minutes, with time related to the database size)
+ [Data Partitioning Feature (DPF)](https://www.ibm.com/docs/en/db2/11.5?topic=environment-setting-up-partitioned-database) has been used or not



![Options shown in the diagram are described in the following tables.](http://docs.aws.amazon.com/prescriptive-guidance/latest/rehost-db2-database-on-aws/images/db2-aws-migration-options.png)


**Note**  
Options 4, 7, and 8 require additional licenses.
For options 1, 8, 9, and 10, the exact outage window is based on the database size.

The following tables show high-level comparisons of the migration options based on the source platform.

## Little-endian platform
<a name="little-endian-platform"></a>


|   | Backup and restore | HADR failover | Backup and restore with log shipping | 
| --- | --- | --- | --- | 
| Outage | Long (related to DB size) | Short | Short | 
| Complexity | Low | Medium | Medium | 
| Extra license | No | No | No | 
| DB size limit | Small to medium size | Any size | Any size | 
| Schema migration required | No | No | No | 
| Supports non-logged transaction | Yes | No | No | 
| DPF support | Yes | No | Yes | 
| Fallback capability | Manual setup | Automatic | Manual setup | 

## Logical replication
<a name="logical-replication"></a>


|   | Q Replication | SQL Replication | AWS DMS | 
| --- | --- | --- | --- | 
| Outage | Short | Short | Short | 
| Complexity | High | High | Medium | 
| Extra license | Yes | No | No | 
| DB size limit | Any size | Any size | Any size | 
| Schema migration required | Yes | Yes | Yes | 
| Performance impact on source database | Low | High | Low | 
| Replication performance for heavy write traffic | Good | Bad | Good | 
| Supports non-logged transaction | No | No | No | 
| DPF support | Yes | Yes | Yes | 
| Fallback capability | Reverse replication | Reverse replication | Reverse replication | 

## Big-endian platform
<a name="big-endian-platform"></a>

In the following table, logical replication includes Q Replication, SQL Replication, InfoSphere CDC, and third-party replication tools.


<table>
<tbody>
  <tr><td rowspan="2"> </td><td rowspan="2">Logical replication</td><td colspan="3">Unload and load</td></tr>
  <tr><td>Optim High Performance Unload</td><td>LOAD FROM CURSOR</td><td>db2move</td></tr>
  <tr><td>Outage</td><td>Short</td><td>Medium</td><td>Varies</td><td>Varies</td></tr>
  <tr><td>Complexity</td><td>High</td><td>Medium</td><td>Medium</td><td>Low</td></tr>
  <tr><td>Extra license</td><td>Depends (See the Logical replication table.)</td><td>Yes</td><td>No</td><td>No</td></tr>
  <tr><td>DB size limit</td><td>Any size</td><td>Medium</td><td>Small</td><td>Small</td></tr>
  <tr><td>Schema migration required</td><td>Yes</td><td>Yes</td><td>Yes</td><td>Yes</td></tr>
  <tr><td>Supports non-logged transaction</td><td>No</td><td>Yes</td><td>Yes</td><td>Yes</td></tr>
  <tr><td>DPF support</td><td>Yes</td><td>Yes</td><td>Yes</td><td>Yes</td></tr>
  <tr><td>Fallback capability</td><td>Reverse replication</td><td>Extract and load new data</td><td>Extract and load new data</td><td>Extract and load new data</td></tr>
</tbody>
</table>