Known issues/migration limitations with online migrations from Oracle to Azure DB for PostgreSQL-Single server

Known issues and limitations associated with online migrations from Oracle to Azure Database for PostgreSQL-Single server are described in the following sections.

Oracle versions supported as a source database

Azure Database Migration Service supports connecting to:

  • Oracle version 10g, 11g, and 12c.
  • Oracle Enterprise, Standard, Express, and Personal Edition.

Azure Database Migration Service doesn't support connecting to multi-tenant container databases (CDBs).

PostgreSQL versions supported as a target database

Azure Database Migration Service supports migrations to Azure Database for PostgreSQL-Single server version 9.5, 9.6, 10 and 11. See the article Supported PostgreSQL database versions for current information on version support in Azure Database for PostgreSQL-Single server.

Datatype limitations

The following datatypes won't be migrated:

  • REF
  • Nested tables
  • User-defined data types
  • Notes
  • Virtual columns
  • Materialized views based on ROWID column

Also, empty BLOB/CLOB columns are mapped to NULL on the target.

LOB limitations

  • When Limited-size LOB mode is enabled, empty LOBs on the Oracle source are replicated as NULL values.
  • Long object names (over 30 bytes) aren't supported.
  • Data in LONG and LONG RAW column can't exceed 64k. Any data beyond 64k will be truncated.
  • In Oracle 12 only, any changes to LOB columns aren't supported (migrated).
  • UPDATEs to XMLTYPE and LOB columns aren't supported (migrated).

Known issues and limitations

  • Customers must use SYSDBA to connect to Oracle.
  • Data changes resulting from partition/sub-partition operations (ADD, DROP, EXCHANGE, and TRUNCATE) won't be migrated and may cause the following errors:
    • For ADD operations, updates and deletes on the added data may return a "0 rows affected" warning.
    • For DROP and TRUNCATE operations, new inserts may result in "duplicates" errors.
    • For EXCHANGE operations, both a "0 rows affected" warning and "duplicates" errors may occur.
  • Tables whose names contain apostrophes can't be replicated.