To recover a dropped or corrupt table with Percona Data Recovery Tool for InnoDB you need two things: media with records(ibdata1, *.ibd, disk image, etc.) and a table structure. Indeed, there is no information about the table structure in an InnoDB page. Normally we either recover the structure from .frm files or take it from [...]
Testing InnoDB “Barracuda” format with compression
April 23, 2008 By 3 Comments
New features of InnoDB – compression format and fast index creation sound so promising so I spent some time to research time and sizes on data we have on our production. The schema of one of shards is
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 | CREATE TABLE `article87` ( `id` bigint(20) unsigned NOT NULL, `ext_key` varchar(32) NOT NULL, `site_id` int(10) unsigned NOT NULL, `forum_id` int(10) unsigned NOT NULL, `thread_id` varchar(255) CHARACTER SET latin1 NOT NULL, `published` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00', `crawled` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00', `subject` varchar(255) NOT NULL, `title` varchar(255) NOT NULL, `url` varchar(255) NOT NULL, `num_links` smallint(6) NOT NULL, `links_in` int(10) unsigned NOT NULL, `cache_author` varchar(255) NOT NULL, `cache_site` varchar(255) DEFAULT NULL, `anchor` varchar(255) NOT NULL, `isthread` tinyint(3) unsigned NOT NULL, `author_id` int(10) unsigned NOT NULL, `inserted` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP, `fromfile` varchar(255) NOT NULL, `language_id` tinyint(3) unsigned NOT NULL, `encoding` varchar(255) NOT NULL, `warning` mediumtext NOT NULL, `is_thread_start` tinyint(3) unsigned NOT NULL, `source` mediumint(8) unsigned NOT NULL, `hash` char(32) NOT NULL, `mod_is` tinyint(3) unsigned NOT NULL DEFAULT '0', `is_adult` tinyint(3) unsigned NOT NULL DEFAULT '0', `bodyuc` mediumtext NOT NULL, PRIMARY KEY (`id`), KEY `ext_key` (`ext_key`), KEY `forum_id` (`forum_id`,`thread_id`,`published`), KEY `site_id` (`site_id`,`published`), KEY `hash` (`hash`), KEY `forum_id_2` (`forum_id`,`is_thread_start`,`published`), KEY `published` (`published`), KEY `inserted` (`inserted`), KEY `forum_id_3` (`forum_id`,`thread_id`,`is_thread_start`), KEY `site_id_2` (`site_id`,`author_id`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1; |
PHP vs. BIGINT vs. float conversion caveat
January 10, 2008 By 27 Comments
Sometimes you need to work with big numbers in PHP (gulp). For example, sometimes 32-bit identifiers are not enough and you have to use BIGINT 64-bit ids; e.g. if you are encoding additional information like the server ID into high bits of the ID. I had already written about the mess that 64-bit integers are [...]
Fixing column encoding mess in MySQL
December 18, 2007 By 32 Comments
Just had an interesting issue with an encoding mess on a column containing non-ASCII (Russian) text. The solution was not immediately obvious so I decided it’s worth sharing. The column (actually the whole table) was created with DEFAULT CHARSET cp1251. Most of the data was in proper cp1251 national encoding indeed. However, because of web [...]
Using CHAR keys for joins, how much is the overhead ?
June 18, 2007 By 18 Comments
I prefer to use Integers for joins whenever possible and today I worked with client which used character keys, in my opinion without a big need. I told them this is suboptimal but was challenged with rightful question about the difference. I did not know so I decided to benchmark. The results below are for [...]
