sql deadlock

the transaction.Three. Lock pending viewInvolving an external lock or a table lock, InnoDB does not automatically detect the deadlock, which requires setting the lock wait timeout parameter innodb_lock_wait_timeout to resolve (the settings need to be cautious), this parameter is not only to solve the deadlock problem, in the concurrency, A large number of transactions cannot be suspended immediately with t

applicationOr from issuing incorrect ad-hoc SQL. The followingInformation may aid in determining the deadlock:Deadlock graph:--------- Blocker (s) -------- --------- waiter (s )---------Resource Name process session holds waitsTX-00090017-000be5c4 398 269x390 154 xTX-00060008-0006b498 390 154x398 269 xSession 269: Did 0001-018e-000095fd session 154: Did 0001-0186-00008596 Session 154: Did 0001-0186-00008596 session 269: Did 0001-018e-000095fd The pre

1222 , Level 16 , Status 50 , Line 1 The lock request timeout period has been exceeded. (3). SQL ServerThere is an internalLock Monitor thread executes deadlock checkWhen the lock Monitor starts a deadlock search for a specific thread, it will identify the resources that the thread is waiting for. Then, it will find the owner of the speci

USER:235/FEECORESV Flags: (0x100045) usr/-flags_idl: (0x1) bsy/-/-/-/-/- FLAGS2: (0x40009)-/-/inc pid:651 o/s info:user:oracle, Term:unknown, ospid:13035 Image:oracle@oratest11 Client Details: O/S Info:user:sky, Term:unknown, ospid:1234 Machine:autobots PROGRAM:JDBC Thin Client Application Name:jdbc Thin Client, hash value=2546894660 Current SQL: UPDATE ******* -----End of information to the other waiting sessions----- Information for thi

Record the troubleshooting and resolution of a deadlock, and record the troubleshootingThis is a sad reminder. I remember last week's busy schedule. The goal is to modify some bugs in the code left by another team. This project is used for OLAP analysis, the Logic Server is mainly responsible for metadata operations, such as information displayed on the page, and the Analysis Server is responsible for executing query statements, because they used mond

Experiments on ORA-60 deadlock Create a table:SQL> create table tbl_ora_60 ( Id number (5 ), Name varchar2 (5) ); SQL> insert into tbl_ora_60 values (1, 'A '); 1 row created. SQL> insert into tbl_ora_60 values (2, 'B '); 1 row created. SQL> commit; Commit complete. SQL>

Recently in the blog site, the reply to other people's database deadlock to avoid problems, has been a few times before the same content, I feel it is necessary to converge into a blog post, convenient for everyone.The approach here is applicable to all databases.The workaround steps are as follows:1. Add Updated_count (integer) field in each table2. Add a row of data, Updated_count = 0:Insert INTO table_x (f1,f2,..., update_count) VALUES (..., 0);3.

A database is a shared resource that is used by multiple users, and when more than one user accesses the data concurrently, multiple transactions are generated in the database and the same data is accessed at the same time. Without control of concurrent operations, incorrect data can be read and stored, which destroys the consistency of the database. Lock is a very important technology to realize concurrency control of database. In the actual application of the lock-related anomalies often encou

** The following is the deadlock information viewed using showinnodbstatus. all records are updated using the primary key index userId. No other indexes have any impact and should not cause deadlocks. Please help us to analyze the cause. ** Table indexes are as follows (... PRIMARYKEY (userId), UNIQUEKEYuserId_UNIQUE (userId), UNIQUEKEYuserName_UNIQUEUSINGBTREE (userName) ENGINEInnoDBAUTO_INCREMENT1DEFAULT... mysql The following is the

if not mybatis, you need to create and close the database connection yourself. extension: Database deadlock Database deadlocks are problems that are frequently encountered by transactional databases such as SQL Server, MySQL, and so on. Unless the database deadlock problem occurs frequently causing the user to be unable to operate, the database

that does not meet the criteria is executed in the transaction, the full table scan is performed, and the row-level lock is raised to a table-level lock, and after many such transactions are executed, it is easy to create deadlocks and blockages. In a similar situation, when the amount of data in a table is very large and the index is too small or inappropriate, a full table scan often occurs, and eventually the application system slows down and eventually becomes blocked or deadlocked.Workarou

the two SQL statements that have occurred, it is not difficult to find the problem: When "Update Tsk_task set Status_id=1064,update_time=now () where status_id=1061 and Mon_time Assuming that "update tsk_task set Status_id=1067,update_time=now () where ID in (9921180)" is executed almost simultaneously, this statement first locks the cluster index (primary key), due to the need to update the STATUS_ ID, you also need to lock some index records for Ke

. On the other hand, the database system has different methods to implement the locking mechanism, and the database systems can also produce special deadlock situations. For example, in Sybase SQL Server 11, a lock method with a minimum lock of 2K per page is not a row-level lock. If a table has a small number of records and the length of the record is short (that is, the record density is high, such as the

This article was reproduced from: http://blog.csdn.net/yuanyuanispeak/article/details/527561671 PrefaceThe database large concurrency operation takes into account the deadlock and lock performance issues. See online most vague (especially update lock), so here is a concise explanation, for the following description of the convenient, here with T1 for a database execution request, T2 represents another request, can also be understood as T1 a thread, T2

considered clearly.The third case of deadlockIf an UPDATE statement that does not meet the criteria is executed in the transaction, the full table scan is performed, and the row-level lock is raised to a table-level lock, and after many such transactions are executed, it is easy to create deadlocks and blockages. In a similar situation, when the amount of data in a table is very large and the index is too small or inappropriate, a full table scan often occurs, and eventually the application sys

transactions to read committed data changes, exclusive locks held to transaction commits or rolled back, but shared locks are released immediately after loading data to memory.2 a repeatable read transaction repeats the same query, any rows read by the transaction are not updated or deleted, the exclusive and shared locks are held to the end of the transaction, and the query result set cannot be deleted and modified, but can be inserted.3 Serializable read transactions can repeat the same query

The deadlock has an important effect on the performance and throughput of the system, and it is found that the deadlock of MIS is mainly because two or more threads (login) preempt the same table data resource. Causing a long time to preempt the same resource is not because the transaction we need to deal with is too complex and too long, often because we forget to commit when the front-end application oper

A typical example of A deadlock between two processes is: Obtain lock A in process T1 and apply for lock B; obtain lock B in process T2 and apply for lock A. Here we will demonstrate this situation: 1. Create a Database named InvDB. 2. Execute the following script to create the person table and fill in two pieces of data: 3. Execute the following query simultaneously in the two windows of SQL Server M

I. Causes and conditions of deadlock1. The concept of deadlockin general, if the same thread calls lock two times, at the first call, because the lock is already occupied, the thread suspends waiting for the other thread to release the lock, but the lock is occupied by itself, the thread is suspended, there is no chance to release the lock, and therefore, it is always suspended waiting, which is called a deadlock (

Tags: use pre updating APP RET primary key index execution plan nod handlePreviously wrote a blog http://leihuang.org/2015/07/22/concurrence-lock/ is how to use optimistic lock to solve concurrency problems, but the project pushed to the line after the error, as follows -08-13 15:12:44 [ERROR] Com.zhubajie.coupon.app.CouponReceiveAppServiceImpl {couponreceiveappserviceimpl.java:50}- # # # Error updating database. Cause:com.mysql.jdbc.exceptions.jdbc4.MySQLTransactionRollbackException:Deadlock fo