Home icon

Extract and migrate data from nested tables with user-defined nested types from Oracle to PostgreSQL

Database Blog



This article provides a comprehensive guide for extracting and migrating complex nested user-defined types (UDTs) from Oracle to PostgreSQL databases, focusing on two key scenarios involving multi-layered nested data structures.

  • The migration process involves multiple steps:
    • Using AWS Schema Conversion Tool (SCT) to convert database schemas
    • Creating Oracle PL/SQL procedures to transform nested data
    • Using AWS Database Migration Service (DMS) to migrate transformed data
    • Utilizing PostgreSQL functions like string_to_array for final data loading
  • Key challenges addressed:
  • Handling nested table types with multiple layers
  • Converting Oracle-specific member functions
  • Preserving data structure integrity during migration
  • Demonstrated migration techniques for:
  • Movie synopsis data with single-layer nested UDTs
  • Movie artist data with multi-layer nested UDTs

The article provides a detailed, technical approach to migrating complex nested data structures between different database systems, emphasizing the importance of careful data transformation and type conversion.



Go to article

The AWS News Feed is currently looking for gold sponsors. If you want to support the AWS community and reach a large audience of AWS professionals, consider sponsoring the AWS News Feed.

Related articles

Dec 29
2023
Convert JSON SQL queries from an Oracle database to a PostgreSQL database
Aug 6
2025
Automate conversion of Oracle SQL to PostgreSQL inside Java applications with AWS SCT
Jun 8
2026
Automate Oracle PL/SQL to PostgreSQL migration with Amazon Bedrock and Strands Agents
Oct 28
2025
Migrate Oracle reference partitioned tables to Amazon RDS or Aurora PostgreSQL with AWS DMS

The AWS News Feed is currently looking for silver sponsors. If you want to support the AWS community and reach a large audience of AWS professionals, consider sponsoring the AWS News Feed.