MySQL Archive: Difference between revisions

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'''MySQL Archive''' is a storage engine for the [[MySQL]] [[relational database management system]]. Users can use this analytic storage engine to create a table that is “archive” only. Data cannot be deleted from this table, only added. The Archive engine uses a compression strategy based on the [[zlib]] library and it packs the rows using a bit header to represent nulls and removes all whitespace for character type fields. When completed, the row is inserted into the compression buffer and flushed to disk by an explicit flush table, a read, or the closing of the table.

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.<ref>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)</ref> MySQL is examining index support for Archive tables in upcoming releases.