A situation caused by two or more processes being unable to proceed (and thus release their locks) because they are blocked by locks on resources held by the other process.

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2
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0answers
28 views

Locks while stream reading and deleting/inserting involving the same tables?

I have a question regarding a potential block/lock situation: I am reading data using a select command, which is then modified externally and uploaded to a temporary table. A stored procedure will ...
3
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1answer
122 views

Understanding & Resolving Deadlock in SQL Server 2008 R2

I am trying hard to figure out what may be going wrong for below shown deadlock graph: I am receiving alerts for deadlocks similar to above for almost every 10 minutes, it's just the query changes, ...
0
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1answer
41 views

Is it possible to have a deadlock in this situation

I am working with SqlServer and Java. I have the following (pseudo) code : begin transaction For each item of a list select the row in db ... update the row End for end transaction ...
0
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0answers
307 views

Deadlocks due to foreign keys (MySQL)

We are in the process of creating a web application using mysql as a data source. We are using spring with hibernate as an ORM framework. We have hundreds of entities with relations (manyToMany \ ...
1
vote
1answer
214 views

How does the table scan in an UPDATE WHERE predicated on an unindexed column work?

I was looking into a deadlock caused by two concurrent UPDATE statements: UPDATE [table] SET [column] = 0 WHERE [unindexed_column] = @id My understanding is that because the column the WHERE is ...
1
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0answers
83 views

Why does this deadlock occur?

We're using MySQL with the INNODB storage engine. The account table is accessed by two different transactions. We didn't expect a deadlock because only one transaction is holding a lock (2): ...
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0answers
39 views

Can a critical section cause deadlock in SQL Server? [duplicate]

We get the next ID for our tables from a separate table with two columns, TABLE_NAME and NEXT_ID. We have a stored procedure which reads the NEXT_ID and then adds an increment to the NEXT_ID. The work ...
2
votes
1answer
92 views

How is it possible that two deletes give a deadlock, if they do have different primary key data

I am getting a deadlock by the same delete stored procedures that is called by two different threads for deleting two concurrent records. The deadlock happened on the primary key index of the X ...
0
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1answer
244 views

SQL Server Deadlock on delete

I have a query like this: with xx as ( SELECT [FilePath], ROW_NUMBER() over (partition by [FilePath] order by [FilePath]) as RowNumber FROM [dbo].[foo] ...
0
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1answer
90 views

How does PostgreSQL decide which query to cancel during deadlock cleanup

I know that PostgreSQL will detect and clear deadlock once it happen by cancelling one of the queries. How does PostgreSQL decide which one to cancel? Is this deterministic or there is some randomness ...
5
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2answers
548 views

How do I query only for committed data while avoid a deadlock

I have a system writing batches of queries as transactions (to maintain coherency), these can be sets of 30-100 queries per transaction. These are done on multiple tables At the same time there are ...
1
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0answers
177 views

SQL server deadlock graph explained

I am testing a scenario or recurrent request that ends up in executing the following store procedure simultaneously ALTER PROCEDURE [dbo].[clear_class]( @classID [int]) AS BEGIN DELETE FROM ...
1
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1answer
59 views

Deadlock scenario, where is this S lock coming from?

I am encountering the below deadlock scenario. Please see the attached object definitions and execution plans. The plans were pulled out of cache from a system where this deadlock does occur. I ...
2
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2answers
180 views

Understanding deadlock XML

Recently a clients website has been receiving many deadlocks. The website and CMS is custom built on asp.net MVC 3. The database is SQL Server 2008. I believe this started occurring when there was ...
1
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0answers
81 views

InnoDB Deadlocks Involving Currency Transactions

We're dealing with InnoDB deadlocks that are affecting our virtual transaction system. LATEST DETECTED DEADLOCK 150210 20:51:03 *** (1) TRANSACTION: TRANSACTION 0 4240405649, ACTIVE 0 sec, process no ...
0
votes
2answers
119 views

Where deadlock happen in mysql

I am unable to read below logs of mysql after executing SHOW ENGINE INNODB STATUS command. Can anyone please help me out where the deadlock has happen? ------------------------ LATEST DETECTED ...
6
votes
4answers
2k views

Are deadlocks a serious problem? [closed]

I have a few production SQL Server instances and I get around 100 deadlock alert emails a day (up to 100 for one server, 150 in total). Is this a problem I should investigate? How many deadlocks are ...
2
votes
1answer
391 views

What happens if two mySQL queries both try to lock the same row at the same time?

So this isn't exactly my strong suit, but here's my basic understanding of the situation: If two threads of the same application both try to execute the same query at the same time, mySQL will ...
5
votes
1answer
694 views

Deadlock due to concurrent updates (with SIU lock)

We have 2 different wcf services which get invoked by a windows service. The methods in those wcf services are updating the same table inside different stored procedures. One thing is for sure: ...
3
votes
1answer
124 views

enabling snapshot isolation level on a database - what to monitor?

I am having problems with frequent deadlocks on a subscription database. I am considering enabling the snapshot isolation level for that database. I am aware that there is an overhead on the tempDb ...
1
vote
1answer
407 views

table partition in order to solve frequent deadlock issues - how would I know if it will work?

I use sql server 2005 enterprise edition and have a subscriber DB - part of a transactional replication - that is used for Business Intelligence purposes - they run reports out of it, and SSIS ...
10
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2answers
859 views

SQL Server Index Update Deadlock

I have 2 queries which when run at the same time are causing a deadlock. Query 1 - update a column which is included in an index (index1): update table1 set column1 = value1 where id = @Id Takes ...
3
votes
1answer
1k views

View last several innodb deadlocks

I see that I can view the latest deadlock in mysql/innodb, but is there a way to view past deadlocks? We have two deadlock issues, one being important and the other not. The less important deadlock ...
1
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1answer
215 views

MySQL Latest Deadlock Explanation

Can someone explain this deadlock to me? It seems as if there are 2 inserts happening within milliseconds of each other with the same Primary Key. I'm not sure how this can cause a deadlock. At most a ...
1
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1answer
314 views

Deadlock detected on CREATE TABLE in PostgreSQL

I'm creating multiple tables asynchronously when I get deadlock detected. Both tables (Table A & B) have FK to one table (Table C) and I get deadlock on relation to Table C. Scripts CREATE TABLE ...
1
vote
1answer
484 views

TRUNCATE in transaction: dead lock

In a unittest we run this: BEGIN; TRUNCATE table1; TRUNCATE table2; ... UPDATE ...; ROLLBACK; Unfortunately this results in a dead lock if a cron job starts and this job operates on table1 and ...
2
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2answers
16k views

SQL Server - How many type of timeout can happen, and how?

When working with SQL Server, there can be multiple application host accessing it, and each application can have one or many connection. Each connection can potentially have multiple transaction ...
5
votes
1answer
604 views

Should an INSERT cause an exclusive lock on a foreign key?

I'm working on a deadlock issue. Process A is doing a simple INSERT into TableA which has a FK to TableB Process B is doing a complicated SELECT on a join that includes TableA and TableB I'll ...
2
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0answers
390 views

Why does a simple select query produce a deadlock? [closed]

I am trying to analyze randomly occurring deadlock problems on an SQL Server 2008 R2 database. The deadlocks occur in very rare cases when SSRS tries to access one of 5 different stored procedures. ...
0
votes
1answer
253 views

Weird deadlock graph

I got a deadlock graph that I cannot completely understand. This is the deadlock graph xml (table names obfuscated, obviously): <?xml version="1.0" encoding="utf-16"?> <deadlock-list> ...
2
votes
0answers
96 views

Deadlock when CODES table has 41900 rows

I'm having a deadlock accessing the same table from two different jobs. I'm testing it on a SQL SERVER 2012 Enterprise edition. Running SQL Profiler I get this graph: You can find the SQL Server ...
0
votes
0answers
122 views

InnoDB says I'm in Deadlock when it should not be

I'll do my best to explain the situation. I'm at a complete loss. Preliminaries I'm running a Java Web Application in Tomcat 7.0 using a JDBC Connector to communicate with my MySQL Database. The ...
1
vote
2answers
302 views

Getting a Deadlock,

I have this code : public void saveItems(List<Pair<Item, MapleInventoryType>> items, int id) throws SQLException { PreparedStatement ps = null; PreparedStatement pse = null; ...
1
vote
1answer
748 views

InnoDB deadlock with INSERT .. SELECT

I am trying to understand why a deadlock occurs when two workers in parallel are running INSERT .. SELECT queries on a table which has both 1) auto incremented primary key, 2) a unique index on ...
17
votes
1answer
2k views

Can foreign keys cause deadlocks and hinder READ COMMITTED SNAPSHOT?

This is a followup question from: http://stackoverflow.com/questions/7684477/is-it-possible-to-set-transaction-isolation-level-snapshot-automatically I'm still having deadlock/timeout situations in ...
0
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0answers
58 views

Is it possible for a SELECT-only stored procedure to deadlock on itself?

Environment is Microsoft SQL Server 2012. Is it possible for a stored procedure consisting exclusively of SELECT statements to deadlock on itself? That is the report I am getting from a vendor for ...
8
votes
1answer
1k views

Why are there Victimless Entries on the Deadlock Graph?

I am trying to learn how to analyze SQL Server 2008's deadlock graph, and I'm finding alot of entries with an empty <victim-list> node. I don't understand what these entries represent: if there ...
0
votes
1answer
70 views

How to create via sql and detect via ERRORLOG SQL Server 2008 Deadlocks

I am designing a monitoring program using HP Sitescope SIS. The goal is detect deadlocks. In doing so, I created a deadlock on an existing but nearly unused SQL Server 2008. I used the following ...
4
votes
1answer
2k views

Side effects of using updlock lock hint?

I was just exploring UPDLOCK hint in SQL-Server 2008 and I found it is very useful in avoiding certain deadlock scenarios. There are always some side effects when using these types of lock hints but I ...
2
votes
2answers
645 views

Help reading deadlock XML

Even with reading the Bart Duncan blog about reading deadlocks I still struggle with this. I have included the XML from a particular deadlock. <?xml version="1.0" encoding="utf-8" ?> - ...
5
votes
1answer
669 views

Why are U locks required when using Read Committed Snapshot Isolation

I consider myself a beginner at Sql Server locking. My understanding is that when using RCSI, Sql Server doesn't need to issue S locks because it uses row versioning (in most cases). From ...
11
votes
1answer
806 views

Resolving deadlock from 2 tables only related through indexed view

I have a situation where I'm getting deadlocks, and I think I've narrowed down the culprits, but I'm not quite sure what I can do to fix it. This is on a production environment running SQL Server ...
3
votes
2answers
788 views

Deadlock with simple queries in sql server 2008

I have an application that must delete and insert registries from a table, the table is storing the historic registries for an access control and is stored with the datetime for the check in the ...
1
vote
1answer
255 views

Deadlock while updating rows and inserting new ones

I'm working with SQL Server 2012 Express Edition and I getting this error: Transaction (Process ID 53) was deadlocked on lock resources with another process and has been chosen as the deadlock ...
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0answers
1k views

exec sp_getapplock - Different behaviour using go or without go

we have a strange behaviour while using sp_getapplock (we tried to use this to solve a problem with a deadlock involving some insert while another session was trying to execute a ALTER SWITCH ...
8
votes
1answer
4k views

Deadlock on Delete Statement

I get a deadlock when a SQL Server Job runs. The deadlock occurs on a simple DELETE statement. I would have thought there would have to be a SELECT/UPDATE query running to cause the deadlock? But ...
4
votes
0answers
862 views

SQL Server Deadlock - Two SELECT Exclusive Locks on Exact Same Index and Key [closed]

How is the deadlock graph below possible? How did two SELECT statements simultaneously acquire an exclusive lock on the exact same resource? The exclusive locks were on the primary key index for ...
0
votes
1answer
412 views

Is UDPLOCK using Row-locks?

I have a UPDATE statement that is using a UPDLOCK inside a DTCTransaction to avoid deadlocks. Now I was wondering. is it locking on a Row-level or on a Table-level?
3
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0answers
50 views

Update+Select in one SQL Server transaction, and concurrent deadlocks [duplicate]

I have a problem with a transaction isolation or concurrent atomic select+update. SQL Server, C++ application, OTL/ODBC, and I can't use any stored procedures. Here is the thing. The task is to ...
20
votes
3answers
16k views

Code to simulate deadlock

I am testing my application I need some code that stable simulates the deadlock on database site (sql script if possible). Thank you. ADDED: Reproducing deadlocks involving only one table