Locking resources

Which of the following commands are not blocking operations? (Choose two.)

❌ UPDATE

✅ INSERT

❌ DELETE

❌ MERGE

✅ COPY

---

The following guidelines apply in most situations:

COMMIT operations (including both AUTOCOMMIT and explicit COMMIT) lock resources, but usually only briefly.

CREATE [ DYNAMIC] TABLE, CREATE STREAM, and ALTER TABLE operations all lock their underlying resources when setting CHANGE_TRACKING = TRUE, but usually only briefly. Only UPDATE and DELETE DML operations are blocked when a table is locked. INSERT operations are NOT blocked.

UPDATE, DELETE, and MERGE statements hold locks that generally prevent them from running in parallel with other UPDATE, DELETE, and MERGE statements.

Most INSERT and COPY statements write only new partitions. Those statements often can run in parallel with other INSERT and COPY operations, and sometimes can run in parallel with an UPDATE, DELETE, or MERGE statement.