New Schema Conversion feature in AWS DMS

New Schema Conversion feature added in AWS Database Migration Service (DMS)

AWS Database Migration Service (AWS DMS) is a key service which is being used by all enterprise customers for migration of databases to AWS securely. DMS Schema conversion is a fully managed feature added to DMS which will assess the source database and covert the database schema. DMS Schema Conversion is a web-version of the AWS Schema Conversion Tool (AWS SCT). Earlier we were deploying the solution in pieces for both AWS DMS and AWS Schema conversion tool for heterogeneous migrations.

AWS is rolling out this feature in multiple regions in phases, it is available in US East (N. Virginia), US East (Ohio), US West (Oregon), Europe (Ireland), Europe (Frankfurt), Europe (Stockholm), Asia Pacific (Sydney), Asia Pacific (Tokyo), Asia Pacific (Singapore).

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In other Region where this feature is not available, we can use the AWS Schema Conversion Tool?and download the AWS Schema Conversion Tool (AWS SCT)?software to the local drive or server.

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Architecture

AWS Database Migration Service (AWS DMS) schema conversion feature architecture details are stated described below.

There are 4 primary components for this new feature:

1. Instance Profile
2. Data Providers
3. Migration Projects
4. Assessment reports

• Instance Profile- For all Network and Security related configuration. We can create instance profile from AWS DMS console navigation pane.
• Data Providers- We need to create two data providers, one for source database and second for the target database. All Database connection credentials are stored here. It also stores information about data store type and location of your database.
• Migration Projects- It stores all the rules which are created for migration and migrate schema, code objects. We can create maximum. We can describe our source database type and target database type in data providers. Migration projects are serverless only. AWS DMS automatically provisions the cloud resources for your migration projects.
• Assessment reports- It will summarize all the schema conversion tasks and action items for schema that can't be converted to the DB engine of your target DB instance.

Other Pre requisites-

1. AWS Secrets Manager- It store your source and target database credentials.
2. AWS Identity and Access Management (IAM)- Create role for S3, Secrets manager.
3. S3- It store information about the migration project.
4. Network for DMS Schema Conversion- DMS schema conversion creates schema conversion instance in a VPC and during creation of instance profile, we need to select the account, VPC and region. We can opt for multiple options to connect source database to target database(single VPC or multiple VPC, Direct connect or VPN or internet connection)

Supported Databases

DMS Schema Conversion supports the following data providers as sources for your migration projects:

• ?Microsoft SQL Server version 2008 R2 and higher
• Oracle version 10.2 and later, 11g and up to 12.2, 18c, and 19c

DMS Schema Conversion supports the following data providers as targets for your migration projects:

• MySQL version 8.x
• PostgreSQL version 14.x

DMS Schema Conversion Limitations

As this is the new feature and evolving, there are few limitations in this feature as compared to legacy Schema Conversion Tool (SCT):

• It does not support command line interface.
• We can't apply filters to the source and target database trees to display only those database objects that meet the filter clause.
• We can't use migration rules to move objects to a new schema.
• ?We can't edit SQL code for the source and target databases in a migration project for DMS Schema Conversion.
• We cannot save the migration project for offline mode