how to avoid deadlock in sql server

Tags: io os sp data on CTI Code BS ASRecently in a large-scale project, because data design uses a discrete database design to facilitate requirements change and user-defined process elements, because the user-defined features, data integrity by code constraints become less realistic, can only rely on the relationship between the table constraints, resulting in data operations often produce X (exclusive) lock, Severely affect data performance.The most straightforward solution to a database

SYS. sysprocesses is an important system view. It is mainly used to locate and solve SQL Server blocking and deadlock. Msdn: contains information about processes running on an SQL server instance. These processes can be client processes or system processes. Main

@intCounter @intCountProperties begin --take the first record Select @spid =spid@bl =BL from#tmp_lock_whowhereId= @intCounter begin if @spid =0 Select 'causing the database deadlock is:'+ CAST(@bl as VARCHAR(Ten))+ 'process number, which executes the following SQL syntax' Else Select 'process number spid:'+ CAST(@spid as VARCHAR(T

Tags: DDR amp ESC sel EPO system datetime Order AddressViewing with extended events for dynamic viewsSELECT xed.value (' @timestamp ', ' datetime ') as Creation_date, xed.query ('. ') As Extend_event from ( SELECT CAST ([Target_data] as XML) as Target_data from sys.dm_xe_session_ Targets as XT sys.dm_xe_sessions as xs on xs.address = xt.event_session_address WHERE Xs.name = N ' system_health ' and xt.target_name = n ' ring_buffer ' ) as Xml

(based on the number of bytes that the transaction needs to write to the transaction log). You can easily resolve this deadlock in 2 tables by providing an index to the Column2. In that case, SQL Server can perform the lookup (seek) operator of a conforming column, so when you execute a SELECT statement, you can skip the locked row that is already in the index l

Label:Write a stored procedure a few days ago, the stored procedure used a transaction, and then I put some code comments out to debug the wrong, suddenly found a table is locked, the original is the code to create a transaction forget to comment out. This table locks the workaround. In fact, not only the situation described above will lock the table, there are many kinds of scenes will make the table life and Death lock, unlocking is actually very simple, the following with an example to explai

1. First we need to determine which user is locked in which table. --Query Locked table Select request_session_id spid,object_name (resource_associated_entity_id) tablename A table that contains the SPID and tablename columns is returned after the query. Where the SPID is the process name and TableName is the table name. 2. Knowing which process has locked the table, you need to find the host that locked the table through the process. --Query host name exec sp_who2 ' xxx ' xxx

An error occurred while attaching the database to SQL Server. The error message is as follows: Error 0: Unable to load DLL Microsoft prompts you to operate SQL database at will to avoid unnecessary trouble or the DLL. Open the query analyzer and execute the following statement: Drop procedure sp_oacreateDrop procedur

four necessary conditions of the joint action produced, so according to the general idea, as long as can break one of them, can effectively avoid the production of deadlocks. The following are the processing that can be made for the four prerequisites: Allows concurrent access to resources. Allow resource deprivation for the process. The resources required for the process to be submitted once. The orderly allocation of re

Tags: Profiler deadlock deadlock Trace transactionSQL Server Profiler-Debug DeadlockTracking generic exceptions is simple, but dealing with deadlocks is difficult, with a deadlock message number of 1205 and a severity of 13. The only suggestion that the server can "rerun the

SQL Server deadlock makes the problem that we often encounter, the deadlock of database operation is unavoidable, this article does not intend to discuss how deadlocks are produced, the focus is to resolve deadlocks. Hopefully it will help you learn about the deadlock in

I. Four Conditions for deadlock 1. Mutual exclusion: resources cannot be shared and can only be used by one process. 2. Hold and wait: processes that have obtained resources can apply for new resources again. 3. No pre-emption: allocated resources cannot be forcibly deprived from the corresponding process. 4. Loop wait condition (Circular wait): several processes in the system form a loop. Each process in the loop is waiting for resources occupied by

[C #] SQL Server Service monitor of WinForm (avoid starting the service at startup ), Since I have just started to write a blog and recently become lazy, I have no time to organize many projects in the past. I will first send a small tool that I have previously written. About MS-SQL service Optimization People who ha

Label:Many times, deadlocks are requested by two or more sessions to hold the other session of the lock while holding other session, but there are some special deadlock only by a single session lock triggered, today saw a related article, transported to share with you! The code that caused the deadlock: Execution Environment SQL

an error. Figure E The access project does not support NZ functions. Use NZ in Access Project NZ cannot be used in the project, but should be replaced by the isnull function of transact SQL. This function is similar to NZ in the following form: Isnull (expression, valueifnull) Both parameters are required. The type of isnull result value is determined by expression. If the column data type of valueifnull conflict

Tags: style blog http io using ar strong data SPTurning on deadlock monitoring in the database collects the deadlock conditions that occur in the database. There are 2 ways to open it:1 Turn on 1222 monitoringExecute SQL statement:DBCC Traceon (1222,-1);Then view the deadlock information in the system log.2 Start

four necessary conditions of a deadlock 1. Mutually exclusive conditions (Mutual exclusion): Resources cannot be shared and can only be used by one process. 2. Request and retention conditions (Hold and wait): a process that has already been resourced can request a new resource again. 3. Non-deprivation (No pre-emption): Resources that have been allocated cannot be forcibly deprived from the corresponding process. 4. Cyclic wait condition (circula

paragraph of SQL, only the update Table2 section is run USE testdb; -- Transaction2 BEGIN TRAN UPDATE table2 SET student_name = student_name + 'Transaction2' WHERE id = 1 UPDATE table1 SET student_name = student_name + 'Transaction2' WHERE id IN (1,2,3,4,5) COMMIT TRANSACTION Run again, the first SQL update table2, run the second SQL