phantom read

1. Some problematic reads in the transaction: dirty read, non-repeatable read, Phantom readThe dirty read (Dirty Read) transaction T1 updated the contents of a row of records, but did not commit the changes. The transaction T2 reads the updated row,

MySQL InnoDB Transaction isolation level dirty read, Repeatable read, phantom read MySQL InnoDB transactions are isolated at four levels. The default value is repeatable read ). · READUNCOMMITTED ). Another transaction modifies the data but has not

First of all, MySQL Phantom read is not "a transaction within two times the same operation actually got a different result", because it is not possible at the RR isolation level using the Read VIEW/MVCC, the definition of this magic is more suitable

Three possible problems of concurrency Dirty read Definition: During the execution of transaction A, transaction B reads the modification of transaction A, but transaction A does not end (COMMIT). Transaction A may succeed or fail later. Metaphor: A

Three possible problems of concurrency Dirty read Definition: During the execution of transaction A, transaction B reads the modification of transaction A, but transaction A does not end (COMMIT). Transaction A may succeed or fail later. Metaphor: A

Database transaction isolation level-dirty read, phantom read, non-repeated read, transaction level I. database transaction isolation level There are four database transaction isolation levels, from low to high: Read uncommitted, Read committed,

Database transaction isolation level and dirty read, phantom read, non-repeated read, transaction level I. database transaction isolation level   There are four database transaction isolation levels, from low to high: Read uncommitted, Read

1. Phantom readingPhantom Reading (Phantom read), also known as virtual reading, refers to the number of data bars in a transaction within two queries, the Phantom reads and does not repeat some types, the same is in the two query process, the

Http://my.oschina.net/u/219582/blog/59834]  1.Dirty read: Dirty read means that when a transaction is accessing data and modifying the data has not been committed to the database, another transaction also accesses the data, then the data is used.

1. Dirty read: Dirty read means that when a transaction is accessing data and modifying the data has not been committed to the database, another transaction also accesses the data, then the data is used. 2. Repeated read is not allowed.: Refers to

1. What is a transactionA transaction is a combination of one or more database operation statements with acid,4 characteristics.Atomicity: Either all succeeds or all is undoneIsolation: Transactions are independent from one another and are not

Original: http://www.cnblogs.com/phoebus0501/archive/2011/02/28/1966709.html Dirty reading is that the data has not been submitted (not necessarily a successful commit), it was used by other affairs.1. Dirty Read : Dirty read refers to when a

1. Dirty read : Dirty read refers to when a transaction is accessing the data, and the data has been modified, and this modification has not been committed to the database, then another transaction also accesses the data, and then used this data. 2.

These are issues that arise from transaction concurrency.There are five levels of transaction isolation:Transaction_none does not use transactions.transaction_read_uncommitted allow dirty reads.Transaction_read_committed prevents dirty reads, the

Article Source: http://www.bkjia.com/sjkjc/806530.htmlThe database's dirty reads, non-repeatable reads, and Phantom reads are all related to the isolation of the transaction. So first look at the 4 major features of the transaction.4 Characteristics

Original text: A brief analysis of the locking problem of SQL Server to prevent the range lock of Phantom read under Serializable isolation levelThe source of this article: http://www.cnblogs.com/wy123/p/7501261.html(It is not the original works

Dirty Read, Phantom Read, and non-repeatable READ + transaction ISOLATION level 1. Dirty read: Dirty read refers to when a transaction is accessing the data, and the data has been modified, and this modification has not been committed to the

1. What is a transactionA transaction is a combination of one or more database operation statements with acid,4 characteristics.Atomicity: Either all succeeds or all is undoneIsolation: Transactions are independent from one another and are not

Original text: A brief analysis of the locking problem of SQL Server to prevent the range lock of Phantom read under Serializable isolation levelThe source of this article: http://www.cnblogs.com/wy123/p/7501261.html(It is not the original works

1, Dirty ReadA transaction is read to another transaction, and a modification that has not yet been committed is a dirty read. Here are the so-called modifications, in addition to the update operation, do not forget that also includesInsert and