“Lock Hashtable Lookups” reports the number of times the lock hash table was searched for a lock on a page, row, or table.
You can configure the size of the lock hash table with the configuration parameter lock hashtable size. If the average number of locks per hash chain is more than four, consider increasing the size of the hash table.
See Chapter 2, “Locking Configuration and Tuning,” in Performance and Tuning Series: Locking and Concurrency Control for more information.
