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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1answer
234 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 ...
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0answers
118 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" ...
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1answer
175 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 ...
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1answer
229 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
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2answers
176 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
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2answers
10k 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
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1answer
229 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
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1answer
694 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
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0answers
258 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. ...
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1answer
205 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
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0answers
92 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 ...
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0answers
94 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 ...
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2answers
213 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
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1answer
403 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
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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 ...
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0answers
43 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
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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
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1answer
60 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
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1answer
1k 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
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2answers
391 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
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1answer
482 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
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1answer
511 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
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2answers
453 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 ...
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0answers
93 views

Ordering a sequence of INSERT…SELECT statements to avoid a deadlock

I have the following two tables in a MySQL database: CREATE TABLE `names` ( `id` bigint(20) unsigned NOT NULL AUTO_INCREMENT, `name` varchar(60) NOT NULL, PRIMARY KEY (`id`), UNIQUE KEY ...
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1answer
131 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
821 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 ...
9
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1answer
2k 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
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0answers
605 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
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1answer
223 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
49 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 ...
15
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3answers
11k 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
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2answers
608 views

Amazon rds MySql -> concurrent connections deadlocks

I normally hang around in StackOverflow but I think this issue is better suited here. I've built an application in C#.NET that uses MySql as a database. My application inserts and updates data in the ...
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0answers
58 views

Query Deadlock on Select Query [closed]

I have 2 queries deadlocking on each other. The first query is Select Top 1 NULL From [Table1] with (HOLDLOCK, TABLOCKX) Second Query is an insert query that only reads from [Table2] to put data ...
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0answers
179 views

What do spikes in InnoDB lock structures indicate?

I co-maintain a high traffic site similar to StackExchange. It runs MySQL 5.1 (working on replacing it with MySQL 5.5 or MariaDB). All our tables are InnoDB. MySQL goes down a couple of times a day. ...
1
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2answers
187 views

Changing two publications at the same time causes deadlock in distribution database

I have transactional replication setup. Let's say three databases on server A replicate to corresponding three databases on Server B. The databases are identical (same structure for different ...
6
votes
0answers
310 views

Is this a race condition or bug in sql server using serializable TIL with updlock? [closed]

I've been staring at this problem for almost a week now. I'm getting a deadlock in some query, and I've reduced the problem to these reproducible steps: Create a database with: create table offering ...
4
votes
1answer
154 views

How can a connection for one DB block a connection to another DB in SQL Server?

We have an interesting scenario. For weeks, we have been experiencing 'outages' on SQL Server 2008 -- where our websites have slowed to a crawl and mass timeouts for all customers who have DB's ...
2
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1answer
126 views

Avoiding Deadlocks

We currently have a trigger-based system in place that does the following: When records in certain tables are modified, a trigger fires that makes a field NULL in a varying number of records in ...
0
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1answer
289 views

SQL Server 2008R2 - Stored Procedure with 2 updates causing deadlocks

I have a web api web service that calls an authentication stored procedure. This stored procedure calls a different stored procedure that does 1 update: UPDATE ...
5
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1answer
3k views

How I prevent deadlock occurrence in my application?

I am developing an LMS application in PHP framework(Codeigniter 2.1.0). I am using MySQL database. All the tables in the database have innodb engine. I also created indexes on each tables. Now I am ...
2
votes
2answers
320 views

Reducing deadlocks with update query hint or other method

I'm getting 20-30 deadlocks per day on the same table. (2 mil rows) Profiler DeadlockGraphs show KEY LOCK and PAGE LOCK (See attched jpg) Total datatype size per row = 114 bytes We have multiple ...
2
votes
1answer
270 views

How to use proper hints for Upsert involving a top 1 subquery

For this specific case (tracking Load Balancer switches) we wish to optimize an Upsert so that it does not exhibit any race conditions, cause any PK violation, or acquire any over sized locks. ...
3
votes
1answer
2k views

PAGELOCK Conversion Deadlock From Update to Intent Exclusive

A customer of ours is experiencing frequent deadlocks. The deadlocks are mostly on the same UPDATE statement. The deadlocks follow a pattern in which both SPIDs have acquired an update (U) lock on a ...
1
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3answers
146 views

Keeping an eye on contention

In SQL Server, I am using the following command to see blocked sessions: select * from sys.sysprocesses where blocked>0 This is super. The problem is I need to see what block sessions there ...
4
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1answer
368 views

Stored procedure deadlocking itself

I have a strange situation, seen from the log: Process 37278 waits for ExclusiveLock on advisory lock [16421,999999,12864385,2]; blocked by process 53807. Process 53807 waits for ExclusiveLock on ...
1
vote
1answer
838 views

How does locking work in INSERT..ON DUPLICATE KEY UPDATE statements?

I am encountering deadlocks while trying to update multiple rows (a batch) using INSERT..ON DUPLICATE KEY UPDATE. Does MySQL lock all the rows in one batch or does it lock only the row it is updating ...
0
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0answers
440 views

Single DELETE statement deadlocking in Sybase ASE

I've got a fairly straightforward process running on ASE 15.7, that creates rows in two tables and later deletes them. The tables are both configured to use datapages for the locking scheme, and the ...
4
votes
1answer
478 views

After 5 years of working, SQL Server 2k5 Table now locking without any changes made to DB

I have a table: OrderDetails. For 5 years, only the odd Deadlock has occured. If it happened, it happened on indexes which was on OrderDetails table Now all of a sudden, deadlocks are everywhere - ...
0
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0answers
114 views

Lock timeouts on a table with two keys, where only one connection writes for a given value of the first key at a time

I have a table user_rollup_message_list that is keyed by (user_id, message_reference). It is a write-heavy table, and gets enough writes that I get many lock timeouts, with a timeout of 50 seconds, ...
3
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2answers
582 views

Can 2 tables lock each other if concurrent read/update do not affect same rows? pagelocks off

Can 2 tables cause a deadlock, if the pagelocks are off, and the rows are not related. E.g. Query 1 runs for a few seconds Select * from Orders where CustomerID = 1 and DateOrdered between @D1 and ...