Migration Assessment

Migration Assessment analyzes object compatibility and SQL compatibility between the source database and the target database before migration. It helps you identify migration risks, estimate required changes, and prepare for the migration implementation. For SQL statements that can be adapted, NineData displays rewritten SQL so you can evaluate and proceed with SQL changes.

NineData currently supports the following migration assessment scenarios:

• MySQL > PostgreSQL
• MySQL > PolarDB PostgreSQL
• MySQL > TDSQL PostgreSQL
• MySQL > He3DB for PostgreSQL
• Oracle > PostgreSQL
• Oracle > PolarDB PostgreSQL
• Oracle > TDSQL PostgreSQL
• Oracle > He3DB for PostgreSQL

Prerequisites

• The source data source used for migration assessment has been added to NineData. For more information, see Add a Data Source.
• The source data source type is MySQL or Oracle.
• The target database type is PostgreSQL, PolarDB PostgreSQL, TDSQL PostgreSQL, or He3DB for PostgreSQL.
• The account that runs the assessment has access permission on the source data source.

Create a Migration Assessment Task

1. Log in to the NineData Console.

2. In the left navigation pane, click Replication > Assessment.

3. On the Assessment page, click Create, and configure the basic task information according to the following table.

   Parameter	Description
   Name	Enter a migration assessment task name for later search and management. The name can contain up to 64 characters.
   Source	Select the source data source to migrate from.
   Evaluate database type	Select the target database type.
   Assessment Content	Select one or more assessment contents: Db Object: Checks whether database structures, including tables and non-table objects, can be used in the target database or require changes. SQL Content: Checks business SQL syntax and function compatibility in the target database and estimates the required SQL changes.
   SQL text collection method	Configure this parameter when the assessment content includes SQL Content. Supported methods: Data collected from the database: Collects SQL execution records directly from the selected database. Import files: Collects SQL from an uploaded SQL file. When this method is selected, manually upload a ZIP, SQL, or TXT file of up to 5 GB in Upload.
   Collect SQL syntax	Configure this parameter when the assessment content includes SQL Content. Select the SQL syntax types to include in the assessment. Other indicates syntax types not explicitly listed on the page.

4. If Assessment Content includes Db Object, or SQL text collection method is Data collected from the database, click Next to configure the object collection scope. Otherwise, click Save and start to create the assessment task.

5. On the Assessment Object page, select the objects to collect. You can select All Objects to collect all source database objects, or select Customized Object, choose objects from Source Object, and click > to add them to Target Object.

6. After configuration, you can perform the following operations:

   • Click Save and start to start the assessment task immediately.
   • Click Save to save the task configuration without starting it. You can later start the task from the Assessment list by clicking Launch.

View Migration Assessment Tasks

1. Log in to the NineData Console.

2. In the left navigation pane, click Replication > Assessment. The migration assessment task list displays all created assessment tasks.

   Parameter	Description
   Task ID	Displays the migration assessment task name and the unique task ID generated by the system.
   Source	Displays the source data source name and connection address in IP:PORT format.
   Evaluate database type	Displays the target database type used for assessment.
   Created by	Displays the user who created the assessment task.
   Created	Displays the creation time of the assessment task.
   Status	Displays the current task status.
   Actions	Provides available operations based on the task status.

View Migration Assessment Task Details

1. Log in to the NineData Console.

2. In the left navigation pane, click Replication > Assessment. Click the target Task ID to open the task details page.

   No.	Section	Description
   1	Task overview	Displays key task information and configuration, including task name, task ID, task status, migration risk level, compatibility percentage, creator, creation time, source and target database types, assessment content, SQL collection method, SQL syntax types, object collection scope, report generation actions, and available task operations.
   2	Assessment Overview	Provides an overall compatibility summary across databases, database objects, data types, and SQL to help you evaluate migration feasibility and risk.
   3	Object assessment detail	Displays object-level assessment results, including object owner, object type, object name, assessment result, assessment status, original DDL, incompatibility reasons, and adapted DDL when available.
   4	SQL assessment detail	Displays SQL-level compatibility results, including the collected or uploaded SQL, database or Schema, SQL type, assessment result, assessment status, original SQL, incompatibility reasons, and rewritten SQL when available.
   5	Replay Detail	Configures and runs SQL traffic replay, then displays replay results. Replay verifies SQL execution on the target database and helps confirm migration risk. For more information, see Configure SQL Traffic Replay.
   6	Report Download	Downloads generated assessment reports. Reports can be downloaded only after report generation is complete.

Configure SQL Traffic Replay

SQL traffic replay sends SQL collected during assessment to the target database for real execution. This verifies SQL compatibility in the target database and further reduces migration risk.

1. Log in to the NineData Console.

2. In the left navigation pane, click Replication > Assessment. Click the target Task ID to open the migration assessment task details page.

3. Click the Replay Detail tab, and then click Configure and start traffic replay.

4. Configure the replay task according to the following table, and then click OK.

   Parameter	Description
   Target Datasource	Select the target data source used for replay.
   Target DB	Select the database used for replay.
   Replay SQL Type	Select the SQL replay mode. Supported values are Raw SQL and SQL after modification. Raw SQL: Executes the original SQL collected from the source database or uploaded file on the target database. SQL after modification: Executes the SQL automatically rewritten by the system on the target database.
   Replay SQL types	Select the SQL types to replay. Supported values include SELECT, INSERT, DELETE, UPDATE, and Other.

Download Assessment Reports

1. Log in to the NineData Console.

2. In the left navigation pane, click Replication > Assessment. Click the target Task ID to open the migration assessment task details page.
3. In the upper-right corner, click Generate an evaluation report or Generate playback report (available only when Assessment replay report exists), and wait until report generation is complete.
4. Click the Report Download tab, and then click Download in the Actions column of the target report to download it.