For AI agents: a documentation index is available at https://www.mongodb.com/docs/llms.txt — markdown versions of all pages are available by appending .md to any URL path.
Docs Menu

Preflight Checks for Migration Jobs

New in version 1.18. :

Relational Migrator runs preflight checks to verify that your source database has the permissions and configuration required by a migration job. The checks run automatically when you create a migration job. They also run during Pre-Migration Analysis, which reports the results on its Prerequisites tab.

When a check fails during job creation, Relational Migrator displays a warning below the Mode selection that summarizes how many checks failed. Click View details to open the Preflight checks failed dialog, which lists each failed check, the tables that the check affects, and the SQL that remediates the failure. To fix the failures, you can copy an individual statement or download a script that contains every fix.

Important

A failed check never blocks the migration. Before you start the migration job, review each failure and run the remediation script with a database administrator. To learn what each check verifies, see the section for your source database.

Preflight checks for Oracle are the verified minimal set of permissions and configuration for each migration mode. A failed check reflects a real requirement, and leaving it unresolved can cause the migration to fail. The following checks run for snapshot migration jobs from an Oracle source database:

Preflight Check
Description

Oracle version 11.1 or later

Verifies that the source runs Oracle 11.1 or later.

The Debezium Oracle LogMiner connector requires this minimum version.

Role: SELECT_CATALOG_ROLE

Verifies that the migration user has the SELECT_CATALOG_ROLE role.

This role grants read access to the data dictionary views that Relational Migrator inspects to check table and log configuration.

SELECT privilege on migrated table

Verifies that the migration user has the SELECT privilege on each migrated table.

Relational Migrator reads rows from each table during the snapshot.

FLASHBACK privilege on migrated table

Verifies that the migration user has the FLASHBACK privilege on each migrated table.

This privilege lets the snapshot read each table at a consistent point in time without blocking concurrent writes.

Preflight checks for MySQL are a best approximation and might be broader or narrower than a specific migration requires. The following checks run for snapshot migration jobs from a MySQL source database:

Preflight Check
Description

MySQL version 5.7 or later

Verifies that the source runs MySQL 5.7 or later.

The Debezium MySQL connector requires this minimum version.

Privileges: SELECT, RELOAD, SHOW DATABASES, REPLICATION SLAVE, REPLICATION CLIENT

Verifies that the migration user has the SELECT, RELOAD, SHOW DATABASES, REPLICATION SLAVE, and REPLICATION CLIENT privileges.

The SELECT privilege reads table data during the snapshot. The connector requires the replication privileges even for snapshot migrations.

Preflight checks for PostgreSQL are a best approximation and might be broader or narrower than a specific migration requires. The following checks run for snapshot migration jobs from a PostgreSQL source database:

Preflight Check
Description

PostgreSQL version 9.4 or later

Verifies that the source runs PostgreSQL 9.4 or later.

The Debezium PostgreSQL connector uses logical decoding, which requires this minimum version.

SELECT privilege on migrated tables

Verifies that the migration user has the SELECT privilege on each migrated table.

Relational Migrator reads rows from each table during the snapshot.

Preflight checks for SQL Server are a best approximation and might be broader or narrower than a specific migration requires. The following checks run for snapshot migration jobs from a SQL Server source database:

Preflight Check
Description

SQL Server version 2008 (10.0) or later

Verifies that the source runs SQL Server 2008 (10.0) or later.

The Debezium SQL Server connector requires this minimum version.

Change data capture enabled on source database

Verifies that change data capture (CDC) is enabled on the source database.

The connector requires database-level CDC even for snapshot migrations.

Preflight checks for DB2 are a best approximation and might be broader or narrower than a specific migration requires. The following checks run for snapshot migration jobs from a DB2 source database:

Preflight Check
Description

Debezium ASNCDC.IBMSNAP_REGISTER table exists

Verifies that the ASNCDC.IBMSNAP_REGISTER table exists.

The connector requires the ASNCDC schema and IBMSNAP_REGISTER table even for snapshot migrations.

Relational Migrator runs no preflight checks for Sybase source databases.