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 due
to the ease with which rows in the data file can be found on
disk: To look up a row based on a row number in the index,
multiply the row number by the row length to calculate the row
position. Also, when scanning a table, it is very easy to read
a constant number of rows 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 rows except
the partially written one. Note that
table indexes can always be reconstructed based on the data
Static-format tables have these characteristics:
Easy to cache.
Easy to reconstruct after a crash, because rows are located in fixed positions.
Usually require more disk space than dynamic-format tables.