MySQL 5.6 Command Line Client - What is the difference between Unicode and MySQL 5.6 Command Line Client

In the old version of MySQL 3.22, the size of a single table of MySQL was limited to 4GB, and the storage engine of MySQL at that time was still the ISAM storage engine. However, when the MyISAM storage engine appeared, that is, since MySQL 3.23, the maximum limit of MySQL single table has been expanded to 64PB (the official document shows). That is to say, from the perspective of the current technical environment, the single table size limit of the MyISAM storage engine of the MySQL database is not determined by the MySQL database itself, but by the file system on the OS of the host where it is located.

　　Innodb, another of the most popular storage engines in MySQL, has two strategies for storing data, one is the shared table space storage method, and the other is the exclusive table space storage method.
　　When using the shared tablespace storage method, all Innodb data is stored in a separate tablespace, and this tablespace can be composed of many files, and a table can exist across multiple files, so its size limit is no longer The file size limit, but its own limit. As can be seen from the official documents of Innodb, the maximum limit of its table space is 64TB, that is to say, the limit of a single table of Innodb is basically around 64TB. Of course, this size includes all indexes and other related data of this table. .
　　When using the exclusive table space to store Innodb tables, the data of each table is stored in a separate file, and the single table limit at this time becomes the size limit of the file system.


Batch modification of the package path introduced in the Java class file in eclipse - [tool use]
Problem:

When copying packages from other projects to the directory of the new project, a red cross appears due to different package paths, and the following classes are required one by one Modifying the package path will be troublesome if there are too many class files. How to change the package path in batches to solve this problem?

Solution:
Method 1:
Ctrl+h >> file serach >> Enter the original package name (type is *.java) >>Replace>> After finding it, enter the package name to be replaced and then choose whether to replace all or part of it.


Method 2:
Modify the error directly Change the name of the package where the class is located, so that you can uniformly modify the package name of all error classes