Transaction Isolation-Level Hints
SQL Server provides a number of hints that you can use in a query to override the default transaction isolation level:
HOLDLOCK—HOLDLOCK
maintains shared locks for the duration of the entire statement or for the entire transaction, if the statement is in a transaction. This option is equivalent to the Serializable Read isolation level. The following hypothetical example demonstrates the usage of the HOLDLOCK
statement within a transaction:
declare @seqno intbegin transaction-- get a UNIQUE sequence number from sequence tableSELECT @seqno = isnull(seq#,0) + 1from sequence WITH (HOLDLOCK) ...
Get Microsoft SQL Server 2014 Unleashed now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.