On Wed, Mar 13, 2002 at 11:00:35AM +0500, Rizwan Majeed wrote: > is there a Raid Mode in MySQL.. I found a RAID_TYPE switch but dont know > much about it.
Here's what I recently wrote about RAID tables. Try to ignore the funny markup. :-) ---snip--- P<RAID tables are just like MyISAM tables except that the data file is split into several data files. Writes to the table are striped across the data files, much like a hardware RAID controller might. This can be helpful in two circumstances. If you have an operating system which limits file sizes to 2GB or 4GB but you need larger tables, using RAID will get you past the limit. If you're have a table which is read from and written to very frequently, you might achieve better performance by storing each of the RAID files on a separate physical disk.> P<To create a RAID table, you must supply some additional options at table creation time:> C< CREATE TABLE mytable ( a INTEGER NOT NULL PRIMARY KEY, b CHAR(18) NOT NULL ) RAID_TYPE = STRIPED RAID_CHUNKS = 4 RAID_CHUNKSIZE = 16 > P<The C<RAID_TYPE> option, while required, must be C<STRIPED> or C<RAID0> which are synonymous with each other. The C<RAID_CHUNKS> parameter tells MySQL how many data files to break the table into. And the C<RAID_CHUNKSIZE> specifies how many kilobytes of data MySQL will write in each file before moving to the next.> P<In the previous example, MySQL would create four sub-directories named C<00>, C<01>, C<02>, and C<03> in which it would store a file named C<mytable.MYD>. When writing data to the table, it would write 16KB of data to one file and then move to the next one. Once created, RAID tables are transparent. You can use them just as you would normal MyISAM tables.> P<With the availability of inexpensive RAID controllers and the software RAID features of some operating systems, there isn't much need for using RAID tables in MySQL.> ---snip--- Does that answer your question a bit? Jeremy -- Jeremy D. Zawodny, <[EMAIL PROTECTED]> Technical Yahoo - Yahoo Finance Desk: (408) 349-7878 Fax: (408) 349-5454 Cell: (408) 685-5936 MySQL 3.23.47-max: up 38 days, processed 1,148,741,462 queries (342/sec. avg) --------------------------------------------------------------------- Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail <[EMAIL PROTECTED]> To unsubscribe, e-mail <[EMAIL PROTECTED]> Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
