Performance Tuning with SQL Server Dynamic Management Views

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Chapter 4: Transactions
Open a tab in SSMS that queries the Culture table, starts a transaction that updates a
row in the table, and keeps the transaction open.
USE DMV ;
GO
SELECT CultureID ,
Name
FROM dbo.Culture ;
BEGIN TRANSACTION
UPDATE dbo.[Culture]
SET [Name] = 'English-British'
WHERE [Name] = 'English' ;
-- COMMIT ;
-- ROLLBACK;
Listing 4.21: Tab 1, query then update the Culture table.
Open a second tab in SSMS and start a transaction that inserts one more row into the
table, and keep the transaction open.
USE DMV ;
GO
BEGIN TRANSACTION ;
INSERT INTO dbo.[Culture] ([CultureID], [Name], [ModifiedDate])
VALUES ('jp', 'Japanese', '2010-08-01') ;
-- COMMIT ;
Listing 4.22: Tab 2, an open transaction that inserts a row into the Culture table.
A transaction running with an isolation level such as REPEATABLE READ will be blocked
if some of the data it needs to read is locked. However, under SNAPSHOT isolation mode,