--Transaction 2 BEGIN TRAN; INSERT INTO dbo.employee (Id, Name) VALUES(6 ,'New'); COMMIT; 由于行更新导致读取缺失和重复读 缺失一个更新行或多次看到某更新行 在READ UNCOMMITTED 级别运行的事务(或使用 NOLOCK 表提示的语句)不会发出共享锁来防止其他事务修改当前事务读取的数据。 在 READ...
--Transaction 2 BEGIN TRAN; INSERT INTO dbo.employee (Id, Name) VALUES(6 ,'New'); COMMIT; 資料列更新造成遺漏讀取和重複讀取 遺漏更新的資料列,或多次看到更新的資料列 在READ UNCOMMITTED 等級(或使用 NOLOCK 資料表提示的陳述式) 執行的...
For more information, see The Transaction Log (SQL Server).The Database Engine converts a partial update to a full update when the UPDATE statement causes either of these actions:Changes a key column of the partitioned view or table. Modifies more than one row and also updates the key of...
import data into a table or view. Optionally, to use multiple matches for bulk importing data, a transaction can specify the BATCHSIZE clause in the BULK INSERT statement. If a multiple-batch transaction is rolled back, every batch that the transaction has sent to SQL Server is rolled back....
For more information on Sch-S and Sch-M locks, seeTransaction locking and row versioning guide. Best practices Consider the following information when you plan to shrink a database: A shrink operation is most effective after an operation that creates unused space, such as a truncate table or...
Errors During Transaction Processing If an error prevents the successful completion of a transaction, SQL Server automatically rolls back the transaction and frees all resources held by the transaction. If the client's network connection to an instance of the Database Engine is broken, any outstandin...
The transaction table is full. All table spaces being rolled forward received I/O errors. Point-in-time table space level roll-forward encountered an I/O error on one of the table spaces being rolled forward. Point-in-time table space level roll-forward encountered an active transaction that...
(X) locks are incompatible with any other lock types 排它所和任何锁都不兼容 (U) locks are compatible with (S) but incompatible with (U) 更新锁和共享锁之间是兼容的,但更新锁与更新锁之间是不兼容的 Simple enough. Next time we will look at transaction isolation levels and see how it affects...
ALTER TABLE nt ...; LOCK TABLE t ... WRITE; If the server acquires metadata locks for a statement that is syntactically valid but fails during execution, it does not release the locks early. Lock release is still deferred to the end of the transaction because the failed statement is writt...
But, assume that the first transaction now deletes the same row from the second table: DELETE FROMt2WHEREid = 2 After executing this statement you should receive the following error message: Transaction (Process ID) was deadlocked on lock resources with ano...