What Is Integrity?


What Is Integrity?

✍: fyicenter.com


Several points about data integrity:

  • Assures database data and structures reflects all changes made to them in the correct sequence.
  • Locks ensure data integrity and maximum concurrent access to data. Commit statement releases all locks. Types of locks are given below.
  • Data Locks protects data i.e. Table or Row lock.
  • Dictionary Locks protects the structure of database object i.e. ensures table's structure does not change for the duration of the transaction.
  • Internal Locks and Latches protects the internal database structures. They are automatic.
  • Exclusive Lock allows queries on locked table but no other activity is allowed.
  • Share Lock allows concurrent queries but prohibits updates to the locked tables.
  • Row Share allows concurrent access to the locked table but prohibits for a exclusive table lock.
  • Row Exclusive same as Row Share but prohibits locking in shared mode.
  • Shared Row Exclusive locks the whole table and allows users to look at rows in the table but prohibit others from locking the table in share or updating them.
  • Share Update are synonymous with Row Share.

2007-04-15, 5060👍, 0💬