# Migration options summary
This table summarizes the main characteristics and considerations for each migration option.
| **Feature** | **In-place migration** [snapshot](table-migration-inplace.md#in-place-snapshot) | **In-place migration** [migrate](table-migration-inplace.md#in-place-migrate) | **Full data migration** [CTAS or (CREATE TABLE \+ INSERT)](table-migration-full.md) |
| --- | --- | --- | --- |
| **Data layout improvements as part of the migration process** | | | |
| [See the AWS documentation website for more details](http://docs.aws.amazon.com/prescriptive-guidance/latest/apache-iceberg-on-aws/migration-options.html) |  No |  No |  Yes |
| [See the AWS documentation website for more details](http://docs.aws.amazon.com/prescriptive-guidance/latest/apache-iceberg-on-aws/migration-options.html) |  No |  No |  Yes |
| [See the AWS documentation website for more details](http://docs.aws.amazon.com/prescriptive-guidance/latest/apache-iceberg-on-aws/migration-options.html) |  No |  No |  Yes |
| [See the AWS documentation website for more details](http://docs.aws.amazon.com/prescriptive-guidance/latest/apache-iceberg-on-aws/migration-options.html) |  No |  No |  Yes |
| [See the AWS documentation website for more details](http://docs.aws.amazon.com/prescriptive-guidance/latest/apache-iceberg-on-aws/migration-options.html) |  No |  No |  Yes |
| **Supported file formats** | Parquet, Avro, ORC | Parquet, Avro, ORC | Parquet, Avro, ORC, JSON, CSV |
| **Source table replacement by an Iceberg table** |  No
(creates a new table, but with additional steps you can replace the source table) |  Yes
(creates a backup table and substitutes the source table with an Iceberg table) |  No
(creates a new table) |
| **Source table impact** | | | |
| [See the AWS documentation website for more details](http://docs.aws.amazon.com/prescriptive-guidance/latest/apache-iceberg-on-aws/migration-options.html) | Corrupts source table | Corrupts backup table | Safe, source unaffected |
| **Iceberg table impact** | | | |
| [See the AWS documentation website for more details](http://docs.aws.amazon.com/prescriptive-guidance/latest/apache-iceberg-on-aws/migration-options.html) | Corrupts Iceberg table | Corrupts Iceberg table | No impact on Iceberg table |
| [See the AWS documentation website for more details](http://docs.aws.amazon.com/prescriptive-guidance/latest/apache-iceberg-on-aws/migration-options.html) | Not visible on new table
(need to incorporate partition with `add_files`) | Not visible on new table
(need to incorporate partition with `add_files`) | Not visible on new table
(need to `INSERT INTO` the new table) |
| **Cost** | Low | Low | Higher (full data rewrite) |
| **Migration speed** | Fast | Fast | Slower |
| **Can be used to migrate to Amazon S3 Tables** |  No |  No |  Yes |
| **Requires manual DDL** |  No
(schema and partitions are copied from source table) |  No
(schema and partitions are copied from source table) | If using CTAS, requires only specifying the partitioning |
| **Best use** | Quick migration without rewriting data, allowing side-by-side use of Hive and Iceberg for testing or gradual transition. | Replacing a Hive table in place without rewriting data, when an immediate switchover is acceptable. | Full Iceberg optimization with data rewrite. Ideal when redesigning partitions or schema, or improving layout and performance. Always recommended if possible. |