About legacy conversion workspaces

Legacy conversion workspaces are an older, more limited type of conversion workspaces. Legacy conversion workspaces don't support Gemini-enhanced conversion features or the interactive SQL editor. You can only use them to convert your source schema with the Ora2Pg migration tool.

Important: Database Migration Service supports Ora2Pg versions 21.1 - 23.2.

We don't recommend using the legacy type of conversion workspaces for your migrations as they present multiple other limitations to the conversion workflow:

Table 1: Conversion workspace feature comparison

Interactive conversion workspace	Legacy conversion workspace
Schema and code object conversion happens in Database Migration Service.	You perform schema and code object conversions outside Database Migration Service by using the Ora2Pg migration tool.
You can apply converted sources to the destination database directly in Database Migration Service.	You are responsible for applying the converted schema to the destination database in your Cloud SQL for PostgreSQL destination instance.
You can test your draft schema and code directly in Database Migration Service to ensure they can be successfully applied to your destination instance.	You can't test your draft schema and code without affecting the destination instance.
Automatically adds missing rowid columns for tables that don't have primary keys and unique constraints.	You must add missing primary keys to destination tables after you apply the schema.

Use legacy conversion workspaces

If your scenario requires the use of legacy conversion workspaces, modify the migration process with the following actions:

1. Write an Ora2Pg configuration file.

   Refer to the Ora2Pg documentation for guidance on how to use the Ora2Pg conversion tool. Expand the following sections for the full list of directives supported in Database Migration Service.

   Ora2Pg configuration supported in Database Migration Service

   Database Migration Service supports the following configuration items for Ora2Pg files:

   • BOOLEAN_VALUES
   • DATA_TYPE
   • DEFAULT_NUMERIC
   • ENABLE_MICROSECOND
   • EXPORT_SCHEMA
   • MODIFY_STRUCT
   • MODIFY_TYPE
   • PG_INTEGER_TYPE
   • PG_NUMERIC_TYPE
   • PG_SCHEMA
   • PRESERVE_CASE
   • REPLACE_AS_BOOLEAN
   • REPLACE_COLS
   • REPLACE_TABLES
   • REPLACE_ZERO_DATE
   • SCHEMA

   Database Migration Service uses connection profiles to define connectivity details, so you don't need to define the following information in your Or2Pg configuration file:

   • ORACLE_DSN
   • ORACLE_HOME
   • ORACLE_PWD
   • ORACLE_USER
   • PG_DSN
   • PG_PWD
   • PG_USER

   Additionally, Database Migration Service doesn't use the WHERE configuration directive to limit the records to migrate.

2. Create a legacy conversion workspace, and upload the Ora2Pg file to convert your schema.

3. Manually apply converted schema to the destination database.

   After you create the Ora2Pg configuration and create the workspace, you must apply the generated code by yourself directly on the destination database.

   Important: With legacy conversion workspaces, you can't test the schema before you migrate. If you encounter any issues when you apply the converted schema, you need to clear the faulty schema from the destination database, adjust your Ora2Pg file, and re-create the legacy conversion workspace with the Ora2Pg file.

4. Migrate tables without primary keys.

   Database Migration Service migrates only tables that have primary keys. If your source database includes tables that don't have primary keys, you need to manually create primary keys or unique constraints in the converted tables in the destination database after you apply the converted schema. For more information and detailed steps, see Add primary key constraints in the destination database.

What's next

After you perform the conversion workflow with the legacy workspace, you can proceed with the standard migration procedures. See Create a migration job.