June 19, 2013

Post: How to find MySQL queries worth optimizing ?

results. What you can think about in this case is removing group by and aggregate functions. Then query would become “select

Post: InnoDB Full-text Search in MySQL 5.6 (part 1)

… The second part will compare query results between MyISAM FTS and InnoDB …mysql> select * from information_schema.innodb_ft_config; +—————————+———+ | KEY | VALUE | +—————————+———+ | optimize_checkpoint_limit | 180 | | synced_doc_id | 1028261 | | last

Post: How to obtain the "LES" (Last Executed Statement) from an Optimized Core Dump?

…duplicates, 3136          lex->ignore))) 3137       { 3138  res= handle_select(thd, lex, sel_result, OPTION_SETUP_TABLES_DONE); 3139         /* 3140           Invalidate the table…Last Executed Statement was found in an optimized core dump by checking the contents of the thd array in the mysql_…

Post: Quickly finding unused indexes (and estimating their size)

select my droppable (unused) indexes from this view: mysql> select * from droppable_indexes; +————–+—————+—————————–+ | table_schema | table_name | index_name | +————–+—————+—————————–+ | sakila | actor | idx_actor_last

Post: InnoDB Full-text Search in MySQL 5.6: Part 2, The Queries!

… ft_min_word_length. First, MyISAM, with MySQL 5.5, on the SEO data set: mysql: SELECT id, title, MATCH(title, body) AGAINST… that term *must* appear in the search results. But does it? With 5.5: mysql: SELECT id, full_name, MATCH(full_name, details…-in replacement for your current MyISAM FTS, the results may surprise you. That last point bears particular emphasis, as it also illustrates…

Post: Percona XtraDB Cluster: Failure Scenarios with only 2 nodes

mysql> select * from percona; +—-+—————+——–+ | id | inserted_from | name | +—-+—————+——–+ | 2 | percona1 | lefred | | 3 | percona2 | kenny | +—-+—————+——–+ 2 rows in set (0.00 sec) percona2 mysql> select

Post: Ultimate MySQL variable and status reference list

MySQL manual, especially the option and…large_pagesblogpercona.commanual last_insert_idblogpercona.commanual Last_query_costblogpercona…Select_full_joinblogpercona.commanual Select_full_range_joinblogpercona.commanual Select_rangeblogpercona.commanual Select_range_checkblogpercona.commanual Select

Post: Percona Replication Manager, a solution for MySQL high availability with replication using Pacemaker

… is its flexibility but flexibility may results in complexity. With the help of…=”ignore” \ last-lrm-refresh=”1322236006″ property $id=”mysql_replication” \ replication_info=”10.2.2.162|mysql-…MySQL. Default is to run select count(*) on mysql.user table, so the user given should at least have select

Post: MySQL Query Cache WhiteSpace and comments

mysql> select count(*) from fact where val like “%c%”; +———-+ | count(*) | +———-+ | 0 | +———-+ 1 row in set (8.79 sec) mysql> select…in set (8.82 sec) Looking at these results you could judge as all problems… change whitespace a bit (see the last query has space after comment deleted…