mysql create schema if not exists example

Mysql CLUSTER: MYSQL cluster  1. References Http://xuwensong.elastos.org/2014/01/13/ubuntu-%E4%B8%8Bmysql-cluster%E5% AE %89%E8%A3%85%E5%92%8C%E9%85%8D%E7%BD% AE/2. Introduction MySQL-Cluster is a technology that allows you to deploy "in memory"

13th. The extensible design of MySQL ReplicationObjective:MySQL Replication is a very distinctive feature of MySQL, and he is able to copy the data from one MySQL server Instance to the Instance of another MySQL server. Although the replication

1. Slow QueryWhen a resource becomes inefficient, it should be understood why. Like the following possible causes:1. Resources are overused and the margin is insufficient to work properly.2. Resources are not properly configured3. Resources are

Traps in the 4.2MySQL schema design Because the MySQL implementation mechanism causes some specific errors, how to avoid them, and slowly: 1. Too many columns The MySQL storage Engine API works by copying data in a row-buffered format at the server

Ru Zhiqiang said in "zookeeper", "Looking at Hongying again, it was not even a half-hour's work that would be delayed, and she never saw her eat a snack, at first glance, you will know that it is a person who will be careful and live." Some people

When you modify a schema by using the Pt-online-schema-change tool, a new table with the same structure as the original data table is created, and the data from the original table is progressively copied to the new table.For example, a ZS table with

Performance-schema was first introduced in MYSQL5.5, but now more metrics are added to performance-Schema in 5.6 and 5.7, and more statistics are available, more and more ORACLE-AWR statistics to catch up, really DBA kids shoes performance diagnosis

Schema and data type optimization Select an optimized data typeHere are some simple principles: Smaller is usually betterIn general, you should try to use the smallest data types that can be stored correctly. Such as: only need to store 0-20

MySQL Performance-Schema (1) configuration table, performanceschema Performance-schema was first introduced in MYSQL 5.5, but now more metrics are added to performance-Schema in MYSQL 5.6 and 5.7, and more statistics are available, more and more

Copyright NOTICE: This article for Bo Master original article, without Bo Master permission not reproduced.Before explaining the system database, let's look at the evolution of MySQL in data dictionaries:MySQL4.1 provides a information_schema data