Spark DDL.md

Spark DDL

comments

alter table some_database.some_table column reason comment 'some comment';

Unclear - but can't add to if source data already delta and already exists? delta specified schema does not match

• https://docs.databricks.com/spark/latest/spark-sql/language-manual/sql-ref-syntax-ddl-comment.html
• https://docs.databricks.com/spark/latest/spark-sql/language-manual/sql-ref-syntax-ddl-alter-table.html

delta lake schema enforcement and evolution

• https://www.databricks.com/blog/2019/09/24/diving-into-delta-lake-schema-enforcement-evolution.html