read lock

MySQL Study Notes summary, mysql Study Notes Slow SQL: A Query whose execution time exceeds the specified time range is called a slow query.In MySQL, how does one record slow SQL statements?A: You can set the following information in my.

Implementation principle of mysqldump and implementation principle of mysqldump MySQL backup can be divided into the following two types: 1. Cold backup 2. Hot Standby Among them, cold backup, as its name implies, is to turn off the database and use

I. Some Concepts in thread synchronization 1.1 concept of critical section (shared area) In a multi-threaded environment, some public resources may need to be used together. These resources may be variables, method logic segments, and so on, these

"Copyright Notice: respect for the original, reproduced please retain the source: blog.csdn.net/shallnet or .../gentleliu, the article is for learning communication only, do not use for commercial purposes"When there are multiple processes in a

http://haohaoxuexi.iteye.com/blog/2119737can be blocked. Cache - BlockingcacheIn the previous section we mentioned the issue of displaying the use of Ehcache locks, in fact we can also implicitly use the Ehcache lock, that is, through the

The company uses the Master-slave structure, on the concrete study under, here records the related content. The benefits of replication Read-write Detach: The primary database is responsible for writing and update data and reads from the

Page level: Engine BDB.Table level: Engine MyISAM, understood to lock the entire table, can be read at the same time, write notRow level: Engine INNODB, separate one-line record lock Table level, locking the entire table directly, and other

First, you need to define the concept of the transaction: a set of atomic SQL queries that, if the database engine succeeds in applying all the statements of the group query to the database, executes the group statement, or none of the statements

Lockfirst, the conceptA lock is a mechanism by which a computer coordinates multiple processes or threads accessing a resource. In the database, the data is a resource shared by many users in addition to the contention of traditional computing

MySQL database Advanced (vii)--Transaction and lock, Transaction introduction 1, Transaction introductionA transaction (Transaction) is a series of operations performed as a single logical unit of work.2, the characteristics of the transactionA,

page level: Engine BDB. Table level: Engine MyISAM, understood to lock the entire table, you can read at the same time, write No Line level: Engine INNODB, a separate row of record lock table level, directly lock the entire table, during your lock,

In order to better optimize MySQL in high concurrency, it is necessary to understand the locking table mechanism when MySQL query is updated.I. OverviewMySQL has three levels of Lock: page level, table level, row level.The MyISAM and memory storage

The following articles mainly introduce the detailed content parsing of locking in the MySQL database table, including internal locking and External Locking. If you are interested in the actual operation content, you can browse the following

The three locking mechanisms of MySQL database locking mechanism is a rule designed by the database to ensure data consistency and enable the access of various shared resources in an orderly manner during concurrent access. MySQL storage engines use

Table locking methods prevent client requests from interfering with each other or mutual interference between servers and maintenance programs. If you close the database, you can ensure that there is no interaction between the server and myisamchk

3. spin lock The most common locks in Linux kernel are spin locks. A spin lock is a mutually exclusive device. It has only two values: "locked" and "Unlocked ". If the lock is available, the lock bit is set, and the code continues to enter the

Author: Liu Lei   This article mainly describes the thread synchronization method in C. There are a lot of online information about the basic concepts of threads. Thread Synchronization is inevitable in multi-threaded applications. In. in the Net

Linux thread synchronization (3)-read/write lock, linux thread I. Overview The read/write locks and mutex functions are similar to that of shared resources in the critical section! The mutex allows only one thread to enter the critical section at a

I. What is file lock? No one will be unfamiliar with the word lock, because there are a lot of locks in our lives, and they play their role in all aspects, the lock function in the world can be summarized as one sentence, that is, to prevent some

I. Opening and creating a file Open the function to open or create a file and return the file descriptor.# Include Int open (const char * filename, int Oflag,.../* [model_t mode] */);Parameter description:Path Name of the file opened or created by