Myiasm is a new version of the Iasm table, with the following extensions:
Portability at the binary level.
NULL column index.
There is less fragmentation than the ISAM table for variable-length rows.
Support for large files.
Better index compression.
A better key? Statistical distribution.
Better and faster auto_increment processing.
The following are some of the details and the specific implementation differences:
1.InnoDB does not support indexes of type Fulltext.
The exact number of rows in the table is not saved in 2.InnoDB, that is, when you execute select COUNT (*) from table, InnoDB scans the entire table to calculate how many rows, but MyISAM simply reads the saved rows. Note that when the COUNT (*) statement contains a where condition, the operation of the two tables is the same.
3. For a field of type auto_increment, InnoDB must contain only the index of that field, but in the MyISAM table, you can establish a federated index with other fields.
4.DELETE from table, InnoDB does not reestablish the table, but deletes one row at a time.
The 5.LOAD table from master operation has no effect on InnoDB, and the workaround is to first change the InnoDB table to a MyISAM table, import the data and then change it to a InnoDB table, but not for tables that use additional InnoDB features, such as foreign keys.
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%"
Any kind of table is not omnipotent, only appropriate for the business type to choose the appropriate table type, to maximize the performance advantage of MySQL.
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