Sql Server 7 – Locking, Questions and answers, 100% Accurare

Sql Server 7 – Locking, Questions and answers, 100% Accurare intent lock--a mechinism used by transactions to declare their intent of acquiring a lock schema lock--used to maintain structural integrity of tables – i.e. cant drop an index while it is being used exclusive lock--needed for data modification update locks--intermediary lock between schared and exclusive. Indicating that a resource wants to obtain an exclusive lock SELECT: holdlocks--shared locks held for duration of transactions shared locks--used for read operations. Data modification is blocked till locks released – multiple shared locks are possible transaction isolation level–– 4 settings--a users isolation level is the level of ability a user has to control a portion of data. The 4 levels are: 1. Read Uncommitted 2. Read Committed 3. Repeatable Read 4. Serializable