Sql count in the innodb and myisam table type query speed

... often used in the sql count (*) or less commonly used count ('column'), how fast innodb and myisam query speed, the principle What is it? Below we first 唠唠myisam and innodb main difference 1). MyISAM is non-transactional security, and InnoDB is transaction-safe. 2). The granularity of...


MyBatis framework and principle analysis

... MyBatis framework and principle analysis MyBatis is an excellent persistence layer framework that supports customized SQL, stored procedures and advanced mapping. It mainly completes 2 things: 1 .Encapsulate JDBC operations 2. Use reflection to open the mutual conversion between Java...


Redis master-slave replication

... 一, Redis supports simple and easy-to-use master-slave replication, which allows the slave server to become an exact replica of the master server. Realize read and write separation and disaster recovery. (The host automatically updates the data according to the configuration and policy...


"Database Clustering Solution" for Architecture Design

... In the previous article, we know that database services may have become a key point or even a bottleneck in the performance of many systems. I also introduced the basic solution of the database server from the primary and secondary architecture, to the master-slave architecture, and...


Mysql error 1205: Lock wait timeout exceeded Solution

... Abstract: Error log: ERROR1205 (HY000): Lock wait timeout exceeded; tryrestarting transaction error Cause: A SQL is executed, but not COMMIT, the latter SQL wants to execute Locked, timeout is over. Solution: showfullprocesslist; then view the table of things: SELECT *FROMinformation...


U010973264's column

... 1. Background In our business needs, we usually need some unique ID to record the identity of one of our data: ID of a user The order number of an order ID of a message Usually we will investigate a variety of generation strategies, according to different business, take the most...


[MySQL] sync_binlog innodb_flush_log_at_trx_commit analyze

... innodb_flush_log_at_trx_commit parameter about mysql First, the parameter interpretation 0: The log buffer will be written to the log file once per second, and the flush (swipe to disk) operation of the log file is performed simultaneously. In this mode, when a transaction is committed,...


2011-2017 China's local government BIM related standard policy summary

... 2018 Before the end of the year, formulate policies and standards for BIM technology application promotion, establish a basic database, reform the construction project supervision method, and form a more mature BIM technology application market. The government invested in hospitals,...


Enterprise Architecture Research Summary (9) - CIO Committee's Enterprise Architecture Implementation Guide for Federal Enterpri

... Development Baseline Enterprise Architecture In the process of developing a baseline enterprise architecture, each enterprise or organization needs Develop various artifacts based on the established architectural goals, scope, and architectural frameworks used, including both the...


Enterprise Architecture Research Summary (3) - Enterprise Architecture Development History

... Learning any theory, I think the best way to get started is to explore its historical roots and development process, and to clarify the real reasons for this theory. Avoid the readers from the beginning of the vortex of the various theories shared by various theories and can not...