VACUUM FULL requires exclusive lock preventing concurrent operations

VACUUM FULL requires ACCESS EXCLUSIVE lock on the table, preventing all other use of the table including SELECT, INSERT, UPDATE, DELETE operations. Standard VACUUM runs in parallel with production operations.

Avoid VACUUM FULL in production. Use standard VACUUM frequently to maintain steady-state disk usage. If VACUUM FULL is necessary, schedule during maintenance window. Consider CLUSTER or ALTER TABLE as alternatives that also require exclusive lock.