mysql deadlock

, inserting the same data concurrently, and a unique key exists in the Insert field.No locks are added during normal insertion, but unique keys are uniquely checked for the unique Key's field, and the record is shared with the lock (S) during the check.When multiple threads add a shared lock (s) to the same row, the shared lock (s) is converted to an exclusive (X) lock, which in turn waits for a deadlock.(2). Update concurrent update, updated fields a

Label:This paper will further explain the locking mechanism of INNODB through the process of solving the deadlock problem in a practical example. Recently, in the project development process, encountered the database deadlock problem, in the process of solving the problem, the author of the MySQL InnoDB engine lock mechanism of understanding gradually deepened.

). Insert and update concurrency, with nonclustered indexes.The deadlock principle is the same as 4.(6) Delete and update concurrency.Principle of the same 2.Deadlock Case Connection:InnoDB Next-key Lock-triggered deadlock:Http://www.cnblogs.com/xhan/p/3701459.htmlDeadlock caused by unique key:Http://www.cnblogs.com/sunss/p/3166550.htmlDelete deadlock in MySQLhtt

The example is as follows: When I used show InnoDB status to check the engine status, I found a deadlock problem: * ** (1) transaction: Transaction 0 677833455, active 0 sec, process no 11393, OS thread ID 278546 starting index read MySQL tables in use 1, locked 1 Lock wait3 lock struct (s), heap size 320 MySQL thread ID 83, query ID 162348740 dcnet03 dcne

Recently, in the project development process, encountered the database deadlock problem, in the process of solving the problem, the author of the MySQL InnoDB engine lock mechanism understanding gradually deepened. The case is as follows: The deadlock problem was found when using show InnoDB status to check engine state: (1) TRANSACTION:TRANSACTION 0 677833455

following two statements SELECT id WHERE coup_usr = ? AND spec_id = ? UPDATE coupon SET coup_num_usr = coup_num_usr + 1 WHERE id = ? AND coup_num_usr ? The first statement finds all the primary key IDs that need to update the rows, and then one more update. In MySQL with InnoDB, the update operation will add row-level locks by default, row-level locks are index-based, and you need to query the MySQL execu

Tags: output ase innodb dead actions htm details recursive MySQL deadlockRecently encountered "TOO deep OR LONG SEARCH in the LOCK TABLE waits-for GRAPH, WE'll roll back following TRANSACTION". Re-review the benefit of a lot of, which the deadlock of the rules, in fact, we have 5 years ago to solve the first version of the second kill scene has been involved, and the idea is very similar, if there is time,

Tags: mysql deadlock unique keyTest environment: MySQL 5.7.18 RR isolation level650) this.width=650; "style=" width:632px;height:261px; "title=" QQ picture 20171027105421.png "Src=" https://s4.51cto.com/ Oss/201710/27/27fa6f262f376b65de32918df8266dfb.png "width=" 741 "height=" 323 "alt=" 27fa6f262f376b65de32918df8266dfb.png "/>Create a table, insert some test dat

This article introduces the solution case of deadlocks caused by loaddata statements in MySQL to coders. it describes some locking mechanisms in the InnoDB engine data table, you can refer to the deadlocks reported by the next online project to briefly describe the causes, solutions, and related points. 1. Background This is a project similar to DATA analysis. DATA is completely imported into an InnoDB table using the load data statement. To facilita

1. The lock mechanism of MySQL common storage engineMyISAM and memory with table-level lock (Table-level locking)BDB with page lock (page-level locking) or table-level lock, default to page lockInnoDB supports row-level locks (row-level locking) and table-level locks, which are row-level locks by default2. Various lock featuresTable-level locks: low overhead, fast lock-up, no deadlock, lock granularity, hig