Updating a table in sql server 2016 easton corbin abigail klein dating
The shared lock on a database level is imposed to prevent dropping of the database or restoring a database backup over the database in use.
For example, when a SELECT statement is issued to read some data, a shared lock (S) will be imposed on the database level, an intent shared lock (IS) will be imposed on the table and on the page level, and a shared lock (S) on the row itself In case of a DML statement (i.e.
While objects are locked, SQL Server will prevent other transactions from making any change of data stored in objects affected by the imposed lock.
In such a case, the update lock will impose another shared lock on the target row.Essentially, locks are in-memory structures which have owners, types, and the hash of the resource that it should protect.