…works with all MySQL storage engines. This set of benchmarks evaluates how well Infobright community edition (ICE) performs in combination with Shard…: create table dim_airport( airport_id int auto_increment primary key, unique key(airport_code) ) as select Origin as `airport_code`, OriginCityName as…
Post: ANALYZE: MyISAM vs Innodb
September 3, 2008 By 9 Comments
…mysql> show index from antest; +——–+————+———-+————–+————-+———–+————-+———-+——–+——+————+———+ | Table | Non_unique | Key…
Post: Duplicate indexes and redundant indexes
August 17, 2006 By 38 Comments
…KEY(id), UNIQUE KEY id(id), KEY id2(id) The logic I heard behind this often – create primary key as object identifier, now we create UNIQUE…MySQL Performance. It is enough to create PRIMARY KEY and it will enforce unique… index and FULLTEXT index, while other combinations may also make sense. Note:…
Post: Find and remove duplicate indexes
June 20, 2012 By 9 Comments
…combinations (A), (A,B), (A,B,C) but not (B) or (B,C). Therefore in the previous example the index ‘key…keys explained before. Lets try it: mysql> show create table t; [...] PRIMARY KEY (`i`), KEY `name` (`name`,`i`), KEY `name_2` (`name`), KEY `name_3` (`name`), KEY…
Post: Using any general purpose computer as a special purpose SIMD computer
May 16, 2011 By 5 Comments
… 6) determine the number of unique words. This is not projected…by the native database interface (MySQL): mysql> select word, md5(word), md5(…NULL ) The other important optimization combines results from multiple queries together….( id bigint auto_increment primary key, prime_number bigint ); spread …
Post: How Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
…time is money your application is not as unique as you think, and we already know … checking for default users in the mysql.* tables, running mk-duplicate-key-checker to find redundant indexes, … changed. Queries can be broken into pieces, combined, or even eliminated entirely (we may suggest caching…
Comment: Duplicate indexes and redundant indexes
September 22, 2006 By 38 Comments
… index it does not make sense to add columns to unique index as it does not improve cardinality. Regarding your question… be better with unique index – after row is read MySQL will not query if there are more rows as in unique key there is no more than one row for each not null combination. It may help also…
Comment: Multiple column index vs multiple indexes
August 25, 2008 By 13 Comments
…Mysql version 5.0.67 ( i was doing testing for bug 29857). mysql> show index from t1000; +——-+————+———-+————–+————-+———–+————-+———-+——–+——+————+———+ | Table | Non_unique | Key…table, t1000c, has same data only combined …
