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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5
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1answer
342 views

Deadlock free MERGE-alike in MySQL?

I am trying to implement some parts of MERGE in the MySQL driver in Drupal. Of course, Drupal has something but in truth it only works because the most frequent MERGE issuer just eats exceptions. So, ...
2
votes
0answers
39 views

innodb update with limit locks all matching (ignores limit)

For a query similar to this: UPDATE myinnotable1 SET value=5,updated=now(),status=1 WHERE status>10 AND message="match msg" LIMIT 1; I found that innodb engine locks ALL rows matching criteria ...
5
votes
2answers
651 views

SQL Server 2000 - 'Performance: Deadlock'

We had to restart our SQL Server today, we had made no changes to it. When it came back up we immediately started getting this error from the server DATE/TIME: 2/27/2014 3:09:31 PM ...
5
votes
3answers
802 views

Deadlock Error from SQL Server 2000 to SQL Server 2008

After migrating data from SQL Server 2000 to SQL Server 2008, when I am doing any a transaction in the table which find out more row on the database, that's gives me error. Transaction (Process ...
0
votes
1answer
371 views

Deadlock caused by INSERT trigger - thread looking for lock it already has?

Using MySQL 5.6.17. I have a table with an INSERT trigger that reads values from that table and 4 other tables, combines the results and writes that to a sixth table. Ever since I added this trigger, ...
1
vote
0answers
51 views

MySQL - Preventing lock wait timeout when deleting rows from self

I have a table of around 500k rows (not big data), that I need to query against itself and then delete some of the rows which don't match the filters. At the moment my query looks like this: DELETE ...
2
votes
0answers
18 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 ...
0
votes
1answer
382 views

MySQL: Transaction and Deadlock

I have table "tbl_data", where have a lot of rows (3 - 5 million). I have JAVA (*.jar) module from which I INSERT/UPDATE data into this table. If I start *.jar file (for example, "run.jar") and after ...
1
vote
1answer
271 views

Deadlock occurring on database, SQL Server 2008R2

Last few days I had major problems with my production site, turns out deadlock occurred, every half an hour maybe 50-60 of them. To do a quick fix in order to keep the site running I set : ...
2
votes
1answer
66 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
votes
1answer
33 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
votes
0answers
53 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
38 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
vote
0answers
62 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): ...
0
votes
2answers
65 views

Why do these concurrent MySQL inserts deadlock?

I am baffled by this deadlock: ------------------------ LATEST DETECTED DEADLOCK ------------------------ 150511 18:42:43 *** (1) TRANSACTION: TRANSACTION B8972CA4, ACTIVE 0 sec inserting mysql ...
0
votes
1answer
47 views

Scale MySQL trigger for thousands of inserts per seconds

We are using MYSQL database for an Analytics app. I have two table token and token-big (for overview of actual data) both have id(int) unix_starttime(int) unix_endtime(int) details(varchar 256) A row ...
0
votes
0answers
38 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 ...
10
votes
1answer
4k views

Deadlock error isn't returning the deadlock SQL

Transaction (Process ID) was deadlocked on lock resources with another process and has been chosen as the deadlock victim. Rerun the transaction. I am getting this error randomly when one of my ...
2
votes
1answer
74 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
votes
1answer
77 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
votes
1answer
29 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 ...
4
votes
2answers
451 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
vote
0answers
81 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 ...
0
votes
1answer
67 views

Please help in understaning DeadLock Graph

<deadlock-list> <deadlock victim="process46d288"> <process-list> <process id="process46d288" taskpriority="0" logused="9968" waitresource="PAGE: 14:1:4468703" ...
6
votes
0answers
513 views

Trace Flag 1222 Not Working?

I have a customer site with two similarly configured 2008r2 SQL Servers "A" and "C". On both servers the trace flags 1204 and 1222 are enabled and DBCC tracestatus shows the following on both ...
1
vote
1answer
55 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 ...
1
vote
2answers
66 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
vote
0answers
49 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
68 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
1k 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 ...
1
vote
1answer
108 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 ...
4
votes
0answers
69 views

When does SQL Server acquire locks?

The list of isolation levels in SQL Server found here states that write locks acquired within a transaction are retained until the end of the transaction. However it doesn't mention anything about ...
3
votes
1answer
180 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
92 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
200 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
votes
2answers
203 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 ...
2
votes
1answer
145 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 ...
0
votes
1answer
189 views

MySQL InnoDB Deadlock For 2 simple insert queries

I have a deadlock for this two insert queries: insert into PlayerClub (modifiedBy, timeCreated, currentClubId, endingLevelPosition, nextClubId, account_id) values (0, '2014-12-23 15:47:11.596', 180, ...
36
votes
6answers
34k views

What are the main causes of deadlocks and can they be prevented?

Recently one of our ASP.NET applications displayed a database deadlock error and I was requested to check and fix the error. I managed to find the cause of the deadlock was a stored procedure that was ...
1
vote
1answer
105 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 ...
0
votes
0answers
30 views

MySQL what is the order of the table lock for this query?

An example query looks like this: INSERT INTO Adventure (sword, fighter, quest) SELECT Swords.id, Fighters.id, Quests.id FROM swords Swords, fighters Fighters, quests Quests WHERE Swords._id = ...
1
vote
1answer
212 views

How many rows will be locked by SELECT … ORDER BY xxx LIMIT 1 FOR UPDATE?

As was asked on stackoverflow but then for MySQL, I was wondering how this works in PostgreSQL. How many rows get locked when I do a "FOR UPDATE" in combination with a "LIMIT", a "ORDER BY" and some ...
0
votes
0answers
107 views

How to fix deadlock caused by “X” locks on same resource?

I have the following <resource-list>: <resource-list> <keylock hobtid="72058301601677312" dbid="7" objectname="myDatabase.dbo.TableOne" indexname="PK_TableOne" id="lock2c336fb380" ...
1
vote
1answer
164 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
203 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 ...
4
votes
2answers
172 views

Insert only deadlocks

We have an application inserting data into a table. Unfortunately, we are getting deadlocks and the deadlocks are coming from inserts only. We are seeing the inserts take key locks in a different ...
2
votes
2answers
9k 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
206 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 ...
4
votes
1answer
624 views

Optimizing concurrent updates in Postgres

I'm running concurrent Postgres queries like this: UPDATE foo SET bar = bar + 1 WHERE baz = 1234 Each query affects the fixed K number of rows, and I can't find a way to enforce the order in which ...
2
votes
0answers
242 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. ...