When the first stream for a table is created, what happens to the table?

• A. A pair of hidden columns are added to the table
• B. A visible column is added
• C. A new index is created
• D. A new trigger is added

Answer: (A)

When you create the first stream on a table, Snowflake adds two hidden metadata columns to support change data capture. These internal columns are not visible in regular queries, but they enable the stream to track what changed (inserts, updates, deletes) since the last offset and to surface those changes when you query the stream. This is how Snowflake provides a changelog-like feed without altering the visible data you work with. The other options aren’t relevant here because Snowflake doesn’t add a user-visible column, won’t create a traditional index, and doesn’t use triggers for streams.