begin tran

1. BusinessIn SQL Servce, a transaction is a unit of work that may contain queries and modify data, as well as modify data definitions, and can also display or implicitly define transaction boundariesShow definition transaction begin TRAN If you

have not been seriously understood UPDATE operation of the lock, recently in MSDN Forums See a problem, ask the heap table update deadlock problem, the problem is very simple, there are similar tables and data: CREATE TABLE DBO.TB ( C1 int,

Although the query speed is a lot of reasons, but if through a certain optimization, you can also make the query problem to a certain extent to be resolved.The reasons for the slow query are many, and the following are common: No index or

1. Four properties of a transactionAtomic Atomicity, consistency consistency, isolation isolation, persistent durability, acid properties.atomicity : A transaction must be a unit of complete work, either fully executed or not executed at

The result set--select query can be used as an alias as a virtual table with Select*from (Select*from score, grade where score.degree between Low and UPP) as Jibieta ble where rank= ' A '--create view (view can only be based on entity table) CREATE

--------------------------------------------------------------------------Author:happyflystone--Date:2009-10-21--Version:microsoft SQL Server 2005-9.00.2047.00 (Intel X86)-APR 14 2006 01:12:25--Copyright (c) 1988-2005 Microsoft

Transferred from: http://blog.csdn.net/eseaqyq/article/details/7795023————————————————————————————————————————————————————Speaking of the deadlock in the data, has been repeatedly encountered in the written questions. Today is a summary of the

Understanding Transactions and LocksTransactions: The essential tool for maintaining logical data consistency and recoverability.Lock: When multiple users access the same database resource, a mechanism for the priority authority management of access,

User feedback said to find duplicate document number, check found that the following document number was assigned to a different two employeesThe system uses the statement exec getnewordernumber ' pwgnumber ', ' PWG ', 1, @pwg_number outputTo

1. Deadlock PrincipleAccording to the definition in the operating system: A deadlock is a permanent wait state in which each process in a set of processes occupies a resource that is not freed, but is placed in a form that is not freed by other

[Reprint: Http://www.3lian.com/edu/2013/12-30/120014.html]1. Upgrading hardware2, according to the query criteria, index, optimize the index, optimize access mode, limit the data volume of the result set.3, expand the memory of the server4. Increase

It is recommended that you read the stored procedure first: SQL Server stored ProcedureØ BusinessIn a database, it is sometimes necessary to run instructions from multiple steps as a whole that either succeeds or fails altogether, which requires a

SQL Server Deadlock Summary1. Deadlock PrincipleAccording to the definition in the operating system: A deadlock is a permanent wait state in which each process in a set of processes occupies a resource that is not freed, but is placed in a form that

SQLServerProfiler is used to monitor and analyze deadlocks in two or more SQLServer processes. When a process locks the resources that other processes attempt to lock, a deadlock occurs. For example, the process process1 holds one exclusive lock (X)

I checked my bookmarks on the Internet tonight and used non-clustered indexes. I used bookmarks to search for bookmarklookup clustered indexes. I didn't use bookmarks to search for my understanding: clustered indexes: Put the content in the book

I. Some batch processing statements have been written in the previous course. These batch processing statements have two problems: 1. parameters cannot be passed for running (customized) Like functions. 2. there is no way to call it repeatedly like

In the sub-stored procedure, a custom error is displayed in the form of raiserror (msg,). An error is displayed in the parent stored procedure, however, the parent transaction is not rolled back during execution. What other configurations do I need?

When there are multiple update operations in a stored procedure, an exception occurs in subsequent update operations. If you do not manually roll back the previously modified data, it will not be automatically revoked!

Principles of database indexing1, to determine whether the operation for the table is a large number of query operations or a large number of additions and deletions to change operations.2, try to build an index to help a particular query. Check

Optimization of ms SQL Server Query Author: xmllover 2007-11-29 There are many reasons for slow query speed. 1. No index or no index is used (this is the most common problem of slow query and is a defect in programming)2. Low I/O throughput,