Vertica Database Locks
When multiple users concurrently access the same database information, data manipulation can cause conflicts and threaten data integrity. Conflicts occur because some transactions block other operations until the transaction completes. Because transactions committed at the same time should produce consistent results, Vertica uses locks to maintain data concurrency and consistency. Vertica automatically controls locking by limiting the actions a user can take on an object, depending on the state of that object.
Vertica uses object locks and system locks. Object locks are used on objects, such as tables and projections. System locks include global catalog locks, local catalog locks, and elastic cluster locks. Vertica supports a full range of standard SQL lock modes, such as shared (S) and exclusive (X).