To enable streams on shared tables, which action must you perform?

• A. ALTER TABLE ... CHANGE_TRACKING = TRUE
• B. Extend data retention
• C. Enable search virtualization
• D. Create a stage

Answer: (A)

Streams need a change-tracking mechanism on the base table to capture what has changed. On shared tables, that means you must turn on change tracking for the underlying table. Running an ALTER TABLE operation to set CHANGE_TRACKING to TRUE enables this, allowing a stream to be created on the table to track inserts, updates, and deletes. Without enabling change tracking, Snowflake cannot produce a stream for that table. The other options don’t enable streams: extending data retention affects how long past data can be accessed, enabling search virtualization isn’t related to change data capture, and creating a stage is about loading data from external locations rather than tracking changes in a shared table.