MySQL database MyISAM and InnoDB storage engine comparison

Reprint: http://www.cnblogs.com/vicenteforever/articles/1613119.html

MyISAM	InnoDB
the difference in composition:	Each myisam is stored as three files on disk. The first file name begins with the name of the table, and the extension indicates the file type. The. frm file stores the table definition. The data file has an extension of. MYD (MYData). The extension of the index file is. MYI (Myindex).	A disk-based resource is a InnoDB tablespace data file and its log file, and the size of the InnoDB table is limited only by the size of the operating system file, typically 2GB
transaction Processing Aspects :	Tables of the MyISAM type emphasize performance, which is performed more quickly than the InnoDB type, but does not provide transactional support	InnoDB provides transaction support transactions, external keys and other advanced database functions
SELECT Update,insert , Delete Operation	If executing a lot of select,myisam is a better choice	1. If your data performs a large number of inserts or UPDATE, for performance reasons, you should use the InnoDB table 2.DELETE from table , InnoDB does not reestablish the table, but deletes one row at a time. 3.LOAD table from MASTER operation does not work for InnoDB, the solution is to first change the InnoDB table to MyISAM table, import data and then change to InnoDB table, However, tables that use additional InnoDB attributes (such as foreign keys) do not apply
to auto_increment	the internal processing of one auto_incremen column per table.    MyISAM for INSERT and The update operation automatically updates this column . This makes the Auto_increment column faster (at least 10%). The value at the top of the sequence cannot be exploited after it has been deleted. (When the Auto_increment column is defined as the last column of a multicolumn index, the use of values removed from the top of the sequence can occur). The   auto_increment value can be used by ALTER TABLE or MYISAMCH to reset    for fields of type auto_increment, The InnoDB must contain only the index of the field, but in the MyISAM table, you can establish a federated index with other fields    better and faster auto_increment processing	If you specify a auto_increment column for a table, the InnoDB table handle in the data dictionary contains a counter called the autogrow counter, which is used to assign a new value to the column. The    autogrow counters are stored only in main memory, not on disk    algorithmic implementations of the calculator, see    Auto_increment column in InnoDB How to work
the exact number of rows in the table	Select COUNT (*) from Table,myisam as long as you simply read the number of rows saved, note that when the COUNT (*) statement contains a where condition, the operation of the two tables is the same	The exact number of rows in a table is not saved in InnoDB, that is, when you execute select COUNT (*) from table, InnoDB scans the entire table to calculate how many rows
Lock	Table lock	Provides row lock (locking on row level), providing no lock read consistent with Oracle type (non-locking read in Selects), in addition, the row lock of the InnoDB table is not absolute, and if MySQL cannot determine the range to scan when executing an SQL statement, the InnoDB table also locks the full table, such as the Update table set num=1 where name like "% aaa% "

MySQL database MyISAM and InnoDB storage engine comparison