…MySQL…rename_tableblogpercona.commanual Com_rename…_column_…queries_in_cacheblogpercona.commanual Qcache_total_blocksblogpercona.commanual Queriesblogpercona.commanual query_alloc_block_sizeblogpercona.commanual query_cache_limitblogpercona.commanual query_cache_min_res_unitblogpercona.commanual query…
Post: Flexviews - part 3 - improving query performance using materialized views
April 4, 2011 By 12 Comments
…is similar to storing the results of a query in Memcache. When the cache “expires”, the contents … old contents (using RENAME TABLE) which means that the view remains available for querying, even during …ignore this column. It is used to prevent wide innodb primary keys on the MV. mysql> select …
Post: Hijacking Innodb Foreign Keys
January 2, 2012 By 2 Comments
… all columns whenever they have changed or not: mysql> set foreign_key_checks=1; Query OK, 0 rows affected (0.00 sec) mysql> select…. Even if you have foreign keys disabled renaming parent table will have reference in child table updated to point to new table… (0.00 sec) mysql> alter table parent rename parentx; Query OK, 0 rows affected (0.05 sec) mysql> drop table parentx; Query OK, 0 rows…
Post: Percona Server 5.5.10 (Release Candidate)
April 4, 2011 By 4 Comments
…-20.0: New Features Added columns ROWS_EXAMINED, ROWS_SENT, and…renamed to slow_query_log_timestamp_always. (Oleg Tsarev) Old system variable slow_query_log_microseconds_timestamp was renamed to slow_query…(Yasufumi Kinoshita) MySQL bugs 56433 and 51325 – These MySQL bugs have been fixed in Percona …
Comment: MySQL Server Memory Usage
September 1, 2006 By 18 Comments
…before_date’, ’0′ ‘Com_rename_table’, ’0′ ‘Com_… ’176788′ ‘Com_show_column_types’, ’0′…not_cached’, ’294363493′ ‘Qcache_queries_in_cache’, ’177′ ‘Qcache_…mysql.sock pid-file=/var/run/mysql/mysql.pid datadir=/db/disk2/mysql/data log-bin=/var/log/mysql/log log-slow-queries=/var/log/mysql/slow-queries…
Comment: Derived Tables and Views Performance
December 14, 2007 By 14 Comments
… world query. In this case the query was of this form: select * from (big inner query) …query syntax was for programming brevity – it’s easier to rename the output columns from the big inner query using the outer query… smarter insertion of the sub-query‘s grouping clauses. MySQL needs quite a bit …
Post: Percona Server and XtraBackup weekly news, March 12th
March 13, 2011 By Leave a Comment
…and progress report. What’s new this week in Percona Server: As you might have seen, we… columns for rows examined, sent, and read. This can be useful for understanding how much progress a query… command-line options and configuration variables will be renamed. We did not always choose good names for…
Post: Implementing efficient counters with MySQL
July 1, 2007 By 16 Comments
…id” and “counter” columns. Using separate table for updates already solves the problem in a lot of…in this case – the script which processes the views within last hour has to run rather complicated group by query…one and process and truncate another. MySQL offers atomic RENAME TABLE call which can be …
Post: Improved InnoDB fast index creation
November 6, 2011 By 4 Comments
…mysql> SET profiling=1; Query OK, 0 rows affected (0.00 sec) mysql> ALTER TABLE t ADD COLUMN v VARCHAR(1); Query…rename result table | 0.161528 | | end | 0.000007 | | Waiting for query cache lock | 0.000002 | | end | 0.000007 | | query…the data is loaded.” mysqldump in Percona Server supports the new …
