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Migration Assessment

Use Migration Assessment to evaluate object and SQL compatibility before you migrate MySQL or Oracle workloads to PostgreSQL-compatible targets.

Overview​

Migration Assessment checks object compatibility and SQL compatibility before you move workloads from the source database to the target database. Use it to identify migration risks, estimate required changes, and prepare the migration plan. When a SQL statement can be adapted, NineData shows the rewritten SQL for review before migration.

Supported assessment paths​

NineData supports the following migration assessment paths:

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

Before you begin​

  • Add the source data source used for migration assessment 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 permissions on the source data source.

Procedure​

Create a migration assessment task​

  1. Sign in to the NineData Console.

  2. Go to Replication > Assessment.

  3. On the Assessment page, click Create, and configure the basic task information.

    Parameter
    		Description
    NameEnter a migration assessment task name for later search and management. The name can contain up to 64 characters.
    SourceSelect the source data source to migrate from.
    Evaluate database typeSelect the target database type.
    Assessment ContentSelect one or more assessment contents:
    • Db Object: Check whether database structures, including tables and non-table objects, can be used in the target database or require changes.
    • SQL Content: Check business SQL syntax and function compatibility in the target database and estimate the required SQL changes.
    SQL text collection methodConfigure this parameter when the assessment content includes SQL Content. Supported methods:
    • Data collected from the database: Collect SQL execution records directly from the selected database.
    • Import files: Collect SQL from an uploaded SQL file. When this method is selected, upload a ZIP, SQL, or TXT file of up to 5 GB in Upload.
    Collect SQL syntaxConfigure 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. 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 you finish the configuration, choose one of the following actions:

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

View migration assessment tasks​

  1. Sign in to the NineData Console.

  2. Go to Replication > Assessment. The migration assessment task list shows all assessment tasks you created.

    Parameter
    		Description
    Task IDShows the migration assessment task name and the unique task ID generated by NineData.
    SourceShows the source data source name and connection address in IP:PORT format.
    Evaluate database typeShows the target database type used for assessment.
    Created byShows the user who created the assessment task.
    CreatedShows the creation time of the assessment task.
    StatusShows the current task status.
    ActionsProvides available operations based on the task status.

View migration assessment task details​

  1. Sign in to the NineData Console.

  2. Go to Replication > Assessment. Click the target Task ID to open the task details page.

    No.
    		Section
    		Description
    1Task overviewShows 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.
    2Assessment OverviewProvides an overall compatibility summary across databases, database objects, data types, and SQL to help you evaluate migration feasibility and risk.
    3Object assessment detailShows object-level assessment results, including object owner, object type, object name, assessment result, assessment status, original DDL, incompatibility reasons, and adapted DDL when available.
    4SQL assessment detailShows 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.
    5Replay DetailUse this tab to configure and run SQL traffic replay, then view replay results. Replay verifies SQL execution on the target database and helps confirm migration risk. For more information, see Configure SQL traffic replay.
    6Report DownloadUse this tab to download generated assessment reports. Reports are available only after report generation finishes.

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. Sign in to the NineData Console.

  2. Go to 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, and then click OK.

    Parameter
    		Description
    Target DatasourceSelect the target data source used for replay.
    Target DBSelect the database used for replay.
    Replay SQL TypeSelect 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 rewritten by NineData on the target database.
    Replay SQL typesSelect the SQL types to replay. Supported values include SELECT, INSERT, DELETE, UPDATE, and Other.

Download assessment reports​

  1. Sign in to the NineData Console.

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

Result​

After the assessment or replay report is generated, download the report and use the compatibility findings to plan schema changes, SQL changes, or migration validation work.

Next steps​