mysql varchar length performance

reason, see section 2. 3 "Select column type ").■ The table rows are fixed only when all the actions in the table are of the fixed length type. Even if only one column in the table is variable-lengthThe row length is also variable.■ The performance advantages of fixed-length rows are completely lost due to the variabl

Original URL: The difference between char and varchar in http://www.jb51.net/article/23575.htmmysql font: [Increase decrease] type: reprinted in MySQL tutorial the difference between char and varchar, are used to store strings, except that they are saved in a different way, Char has a fixed length, and

Tags: change use the values Nod concat distinguish style storage space is simpleCHAR is similar to a varchar type and is used to store strings, but they are saved and retrieved in different ways. Char is a fixed-length character type, and varchar is a variable-length character type.

Tags: number war 4.0 COM English SQL form garbled problem blanka prefaceWhat does a varchar (n) n mean, and how many Chinese characters can be stored? is a commonplace problem, and today was a development colleague asked me about this issue, simply write an article to specifically introduce.Two theoretical knowledgeLet's start by explaining the definition of varchar in MySQL's historical version:4.0 version

1, the logical meaning of varchar (N)Starting with MySQL4.1, n in varchar (n) refers to the maximum number of characters (characters) that can be stored in the field, not the number of bytes. Whether it's a Chinese-English character or a number, or a kanji, it's a character. Before 4.1, n represents the maximum number of bytes of storage (bytes). 2, varchar (N)

In the MySQL tutorial, the difference between char and varchar is used to store strings, except that they are saved in a different way, Char has a fixed length, and varchar is a variable-length character type.The difference between char and varcharCHAR (13) fixed

You see this article from HTTP://WWW.CNBLOGS.COM/AYANMWReprinted from: http://blog.csdn.net/daydreamingboy/article/details/6310907Analyze the length of the MySQL data typeMySQL has several data types that can limit the "length" of a type, with char (length), VARCHAR (

, a text is a case-insensitive blob. 4. Summarize Char,varchar,text DifferencesThe length of the difference, Char range is 0~255,varchar the longest is 64k, but note here 64k is the length of the entire row, to consider the other column, and if there is not NULL when it will occupy a bit, for different character sets,

Tags: hint strong and denotes maximum information judgment field conversionThe difference between varchar and char in MySQL (GO)What is the maximum length of varchar in MySQL?one. VarChar Storage rules:4.0 versions,

follows:The CHAR and VARCHAR types are declared with a length that indicates the maximum number of characters you want to store. For example, CHAR (30) can hold up to 30 characters. Obviously, the official document says that when the mysql version is earlier than 4.1, the statement is true: varchar (5) saves 5 bytes,

default NULL, the maximum length of the varchar field is 65,532 bytes, which is 65535-2-1=65532 bytes On physical storage, varchar uses 1 to 2 extra bytes to represent the actual stored string length (bytes). If the maximum length of a column is less than 256 bytes, it is r

I. Evolution: The varchar type of MySQL database has a maximum length limit of 255 in the version below 5.0.3, and its data range can be 0~255. In the MySQL5.0.3 and above versions, the length of the varchar data type is supported to 65535, which means that 65,532 bytes o

Description of MySQL database varchar restriction rules bitsCN.com MySQLDatabaseVarcharWhat is the maximum length? In fact, this is not a fixed number. the length of varchar isRestriction rules. In this article, we will introduce the var