(mysql.info.gz) Static format

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(mysql.info.gz) MyISAM table formats

(mysql.info.gz) MyISAM table formats

(mysql.info.gz) Dynamic format

 
 14.1.3.1 Static (Fixed-Length) Table Characteristics
 ....................................................
 
 Static format is the default for `MyISAM' tables.  It is used when the
 table contains no variable-length columns (`VARCHAR', `BLOB', or
 `TEXT'). Each row is stored using a fixed number of bytes.
 
 Of the three `MyISAM' storage formats, static format is the simplest
 and most secure (least subject to corruption). It is also the fastest
 of the on-disk formats. The speed comes from the easy way that rows in
 the data file can be found on disk: When looking up a row based on a
 row number in the index, multiply the row number by the row length.
 Also, when scanning a table, it is very easy to read a constant number
 of records with each disk read operation.
 
 The security is evidenced if your computer crashes while the MySQL
 server is writing to a fixed-format `MyISAM' file. In this case,
 `myisamchk' can easily determine where each row starts and ends, so it
 can usually reclaim all records except the partially written one. Note
 that `MyISAM' table indexes can always be reconstructed based on the
 data rows.
 
 General characteristics of static format tables:
 
    * All `CHAR', `NUMERIC', and `DECIMAL' columns are space-padded to
      the column width.
 
    * Very quick.
 
    * Easy to cache.
 
    * Easy to reconstruct after a crash, because records are located in
      fixed positions.
 
    * Reorganization is unnecessary unless you delete a huge number of
      records and want to return free disk space to the operating
      system. To do this, use `OPTIMIZE TABLE' or `myisamchk -r'.
 
    * Usually require more disk space than for dynamic-format tables.
 
 

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(mysql.info.gz) MyISAM table formats

(mysql.info.gz) MyISAM table formats

(mysql.info.gz) Dynamic format