What is record locking in SQL Server?

Locks are held on SQL Server resources, such as rows read or modified during a transaction, to prevent concurrent use of resources by different transactions. For example, if an exclusive (X) lock is held on a row within a table by a transaction, no other transaction can modify that row until the lock is released.

What is record locking in a database?

Record locking is the technique of preventing simultaneous access to data in a database, to prevent inconsistent results. The classic example is demonstrated by two bank clerks attempting to update the same bank account for two different transactions. Clerks 1 and 2 both retrieve (i.e., copy) the account’s record.

How do you avoid locking in SQL Server?

The following methods can be used to reduce lock contention and increase overall throughput:

  1. Avoid situations in which many processes are attempting to perform updates or inserts on the same data page.
  2. Avoid transactions that include user interaction.
  3. Keep transactions that modify data as short as possible.

What are types of locks in SQL?

At the table level, there are five different types of locks:

  • Exclusive (X)
  • Shared (S)
  • Intent exclusive (IX)
  • Intent shared (IS)
  • Shared with intent exclusive (SIX)

How many types of locks are there in SQL Server?

At the table level, there are five different types of locks: Shared (S) Exclusive (X)

What is database lock in SQL?

What is a database lock in the context of SQL? When two sessions or users of database try to update or delete the same data in a table, then there will be a concurrent update problem. In order to avoid this problem, database locks the data for the first user and allows him to update/delete the data.

How do I stop my database from locking?

When an object is being accessed concurrently by multiple programs or users, consider increasing free space, causing fewer rows to be stored on a single page, at least until data is added. The fewer rows per page, the less intrusive page locking will be because fewer rows will be impacted by a page lock.

Why lock is important in SQL?

We know that multiple users can access databases at the same time. As a result, locking is essential for a successful transaction and protects data from being corrupted or invalidated when several users attempt to read, write, or update a database.

How to find blocking queries in SQL Server?

Session Id

  • Login Name
  • Database Name
  • Transaction Begin Time
  • The actual query that is executed
  • What are SQL Server deadlocks and how to monitor them?

    Check the system_health session for deadlocks

  • Create an extended event session to capture the deadlocks
  • Analyze the deadlock reports and graphs to figure out the problem
  • If it is possible to make improvements or changing the queries involved in the deadlock
  • What is row level locking in SQL Server?


  • Multiple Active Results Sets (MARS)
  • Online indexing
  • How to select latest record in SQL Server?

    – SELECT LAST (CUSTOMER_NAME) AS LAST_CUSTOMER FROM CUSTOMERS; – After that query, you will find the result: – SHIKHA SRIVASTAV