Re: Partition problem (Data striping)

[Mattias Jonsson]

For MyISAM it should be something like this:

CREATE TABLE t
(a ...,
PRIMARY KEY (a,...))
ENGINE = MyISAM
PARTITION BY HASH (a)
(PARTITION p0 DATA DIRECTORY = '/disk0/d0' INDEX DIRECTORY = '/disk0/i0',
PARTITION p1 DATA DIRECTORY = '/disk1/d1' INDEX DIRECTORY = '/disk1/i1',
PARTITION p2 DATA DIRECTORY = '/disk2/d2' INDEX DIRECTORY = '/disk2/i2',
PARTITION p3 DATA DIRECTORY = '/disk3/d3' INDEX DIRECTORY = '/disk3/i3',
PARTITION p4 DATA DIRECTORY = '/disk4/d4' INDEX DIRECTORY = '/disk4/i4',
PARTITION p5 DATA DIRECTORY = '/disk5/d5' INDEX DIRECTORY = '/disk5/i5');

Also note that you currently cannot alter DATA/INDEX directory. You have to set them up at CREATE (or do unsupported stuff like manually move the data/index files and symlink to them).

Yet another note is that table scanning is done one partition at a time, but ordered (index) reads may give you a striping access pattern.