DBMS: Exclusive Locks (Definitions)

 "A lock that may not coexist with any other lock on the same object." (Peter Gulutzan & Trudy Pelzer, "SQL Performance Tuning", 2002)

"A lock used during WRITE operations." (Owen Williams, "MCSE TestPrep: SQL Server 6.5 Design and Implementation", 1998)

"A lock that prevents any other transaction from acquiring a lock on a resource until the original lock on the resource is released at the end of the transaction. An exclusive lock is always applied during an update operation (INSERT, UPDATE, or DELETE)." (Microsoft Corporation, "SQL Server 7.0 System Administration Training Kit", 1999)

"This type of lock prevents any other transaction from acquiring a lock on a resource until the original lock on the resource is released at the end of the transaction." (Anthony Sequeira & Brian Alderman, "The SQL Server 2000 Book", 2003)

"A lock on a database element that prevents other transactions from updating or viewing the database element while the lock is held." (Jan L Harrington, "SQL Clearly Explained" 3rd Ed., 2010)

"A lock that prevents any other transaction from acquiring a lock on a resource until the original lock on the resource is released at the end of the transaction." (Microsoft, "SQL Server 2012 Glossary", 2012)

"The type of lock taken by the DBMS when data is modified to prohibit other processes or users from reading or modifying the same data." (Craig S Mullins, "Database Administration", 2012)

"A lock that prevents concurrently executing application processes from accessing database data. See also gross lock, shared lock." (Sybase, "Open Server Server-Library/C Reference Manual", 2019)

"Locks which prevent any other transaction from acquiring a lock until the original lock is released at the end of a transaction, always applied for update (insert, update, delete) operations." (Karen Paulsell et al, "Sybase SQL Server: Performance and Tuning Guide", 1996)