MySQL Archive
Type | Database engine |
---|---|
License | GNU General Public License |
Website | mysql |
Archive is a storage engine for the
One of the current restrictions of Archive tables is that they do not support any indexes, thus necessitating a table scan for any SELECT tasks. Archive tables, however, are supported by the MySQL Query Cache, which can dramatically reduce response times for Archive table queries that are repetitively issued.[1] MySQL is examining index support for Archive tables in upcoming releases.
The engine is not
Despite the use of zlib, archive files are not compatible with gzio, the basis of the gzip tools. It uses its own azio system that is a fork of gzio.
Archive differs from the other MySQL analytical engine, MyISAM, by being a row-level locking engine and by keeping a constant version snapshot throughout a single query (making it MVCC). This means that Archive does not lock for concurrent bulk inserts. For bulk inserts it performs an interlaced INSERT, so unlike MyISAM, order is not guaranteed.
Users can use the archive_reader tool to take an online snapshot of a table and to change the characteristics of an archive file.
To create an Archive table, specify the following engine string:
create table t1 (
a int,
b varchar(32))
ENGINE=ARCHIVE
The MySQL Archive Storage Engine was authored and is maintained by Brian Aker. It was introduced in 2004 with MySQL 4.1.
References
- ^ https://web.archive.org/web/20100212100829/http://dev.mysql.com/tech-resources/articles/storage-engine.html The MySQL 5.0 Archive Storage Engine (archive date 20100212)
External links