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
332 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, ...
0
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1answer
43 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
21 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
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2answers
427 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 ...
0
votes
1answer
319 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 ...
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0answers
51 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
143 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
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1answer
245 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 : ...
0
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1answer
45 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" ...
5
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0answers
362 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
52 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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0answers
49 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 ...
1
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2answers
46 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 ...
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0answers
32 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
44 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
62 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 ...
2
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0answers
41 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
108 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
83 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
135 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
145 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
65 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
99 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, ...
35
votes
6answers
31k 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
60 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
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0answers
25 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
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1answer
163 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
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0answers
88 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
110 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
156 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 ...
3
votes
2answers
150 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 ...
1
vote
2answers
8k 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
144 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
428 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
189 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
183 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
87 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
139 views

notification email when deadlock is encountered in alert log,oracle

how to send a notification email when deadlock is encountered in alert log on any node like the deadlocks encounterd below (an alert any time a deadlock is detected in alert log.) Node 1: Mon Sep ...
0
votes
0answers
72 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 ...
0
votes
2answers
184 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
252 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 ...
16
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
votes
0answers
39 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
57 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
658 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
299 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
426 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 ...
10
votes
1answer
430 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 ...