Convert DDL to CDC

Understanding DDL and CDC file formats

DDL stands for Data Definition Language. It is a set of SQL commands used to define and modify database structures such as tables, indexes, and schemas. DDL files typically contain SQL statements like CREATE TABLE, ALTER TABLE, and DROP TABLE. These files are plain text and are used to set up or modify the structure of a database.

CDC stands for Change Data Capture. CDC files are used to record changes (inserts, updates, deletes) made to a database over time. These files are often used in data warehousing, ETL (Extract, Transform, Load) processes, and database replication. The CDC format can vary depending on the database system, but it generally contains a log of data changes rather than schema definitions.

How to convert DDL to CDC

Converting a DDL file to a CDC file is not a direct file format conversion. DDL files define the structure of a database, while CDC files capture data changes. To generate CDC data from a DDL file, you must:

• Apply the DDL statements to create the database schema in a supported database system (e.g., PostgreSQL, SQL Server).
• Enable CDC or a similar change tracking feature in the database.
• Perform data operations (insert, update, delete) on the tables.
• Export the resulting CDC logs or files from the database system.

Recommended software for DDL to CDC conversion

The best approach is to use a database system that supports CDC natively. Here are some recommended tools and steps:

• SQL Server:
  1. Run your DDL file using SQL Server Management Studio (File → Open → File).
  2. Enable CDC on the database and tables (EXEC sys.sp_cdc_enable_db and sys.sp_cdc_enable_table).
  3. Perform data changes, then extract CDC data using system tables or export tools.
• PostgreSQL (with logical replication or third-party tools like Debezium):
  1. Apply the DDL file using psql or a GUI tool.
  2. Set up logical replication or use Debezium to capture changes.
  3. Export the CDC data as needed.

There is no standalone converter that directly transforms a DDL file into a CDC file, as CDC data depends on actual data changes in a live database.

Summary

To convert a DDL file to a CDC file, you must first create the database schema using the DDL, enable CDC in your database system, perform data operations, and then export the CDC logs. SQL Server and PostgreSQL (with Debezium) are recommended for this workflow.