Re: Covering Index without the data file (myisam)
Am 24.11.2012 22:02, schrieb Hank: Hello everyone, I know this is a longshot, but is there any way to eliminate the MYD file for a table that has a full covering index? The index is larger than the datafile, since it contains all the records in the datafile, plus a second reverse index. It seems redundant to have to also store a MYD file simple answer: NO signature.asc Description: OpenPGP digital signature
Re: Covering Index without the data file (myisam)
MyISAM can't do this but innodb can. If you change to an innodb table and define your index as the primary key then row data is clustered with the primary key. This means there is no additional storage overhead for the primary key because it is just the row data. This will break down if you define secondary indexes though because the primary key is copied for each secondary index. http://dev.mysql.com/doc/refman/5.0/en/innodb-index-types.html On Sat, Nov 24, 2012 at 1:15 PM, Reindl Harald h.rei...@thelounge.net wrote: Am 24.11.2012 22:02, schrieb Hank: Hello everyone, I know this is a longshot, but is there any way to eliminate the MYD file for a table that has a full covering index? The index is larger than the datafile, since it contains all the records in the datafile, plus a second reverse index. It seems redundant to have to also store a MYD file simple answer: NO -- Eric Bergen eric.ber...@gmail.com http://www.ebergen.net -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/mysql
Re: Covering Index without the data file (myisam)
Hello, Well, you have just invented what is known as index organized tables. The MyISAM engine does not implement those. If it did, it would have to deal with quite a few circumstances unique to IOTs. One such circumstance is degradation of efficiency with the increase of record length, another is bloating the size of secondary indexes, and there is quite a few more... In short, the alternative to keeping the MYD file would be much worse :-) Peace Karen. On 24.11.2012, at 13:02, Hank wrote: Hello everyone, I know this is a longshot, but is there any way to eliminate the MYD file for a table that has a full covering index? The index is larger than the datafile, since it contains all the records in the datafile, plus a second reverse index. It seems redundant to have to also store a MYD file. Thanks, -Hank -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/mysql -- MySQL General Mailing List For list archives: http://lists.mysql.com/mysql To unsubscribe:http://lists.mysql.com/mysql
