…] (inclusive). Quorum is computed using weighted sum over group members. Percona XtraDB Cluster binary will …included the old version of innotop. Fixed by removing innotop and its InnoDBParser Perl… hanging. Bug fixed #1130888 (Seppo Jaakola). If MySQL replication threads were started before running …
Post: More on MySQL transaction descriptors optimization
April 26, 2013 By Leave a Comment
… boxes to see if different hardware has any…_list overhead created by concurrent updates. Once… 2000M innodb_log_files_in_group = 2 innodb_file_per…mysql-user=root –mysql-db=sbtest8t1M –mysql-table-engine=INNODB –mysql-socket=/tmp/mysql.sock –oltp-point-selects=1 –oltp-simple-ranges=0 –oltp-sum…
Post: Benchmarking Percona Server TokuDB vs InnoDB
May 7, 2013 By 32 Comments
…, sbtest$I_r1000, with roll-up sum for 10, 100, 1000 records in…selects by `id`. However it will interesting how both InnoDB and TokuDB performs if…file_size = 4G innodb_log_files_in_group = 2 innodb_log_block_size=4096…threads = 1 myisam_recover socket=/var/lib/mysql/mysql.sock user=root skip-grant-…
Post: Speeding up GROUP BY if you want aproximate results
March 7, 2008 By 24 Comments
… so I could trick MySQL to do group by a hash of the page instead of page itself: mysql> select sum(cnt) from (select count(*) cnt from performance_log_080306 group by crc32(page) having cnt>3) pv -> ; +———-+ | sum(cnt) | +———-+ | 1127031…
Post: Using GROUP BY WITH ROLLUP for Reporting Performance Optimization
September 17, 2007 By 14 Comments
… sum values on the application side. Which is the second way. mysql> select grp, count(*) cnt from dt where slack like “a%” group by… slower than standard group by even though the only thing it needs to do is maintain an extra count. So if MySQL does not allow us to use ORDER BY together with GROUP BY WITH ROLLUP can we still do…
Post: How to convert MySQL's SHOW PROFILES into a real profile
February 20, 2012 By 12 Comments
… database to demonstrate: mysql> SET profiling=1; mysql> pager cat > /dev/null mysql> SELECT * FROM …SUM(DURATION) / COUNT(*) AS “R/Call” FROM INFORMATION_SCHEMA.PROFILING WHERE QUERY_ID = @query_id GROUP BY STATE ORDER BY… subtract the SUM(DURATION) from the query’s real response time. If there were,…
Post: MySQL 5.6 vs MySQL 5.5 and the Star Schema Benchmark
March 11, 2013 By 7 Comments
…: Default config for MySQL 5.5 and MySQL 5.6, no tuning at all Config 2: MySQL 5.6 with all …and s_region = ‘AMERICA’ group by d_year, p_brand order by d_year, p_brand; — Q2.2 select sum(lo_revenue), d_…’ group by d_year, s_city, p_brand order by d_year, s_city, p_brand; And the schema: DROP TABLE IF…
Post: Flexviews - part 3 - improving query performance using materialized views
April 4, 2011 By 20 Comments
…_id, ‘> sum(total_price) total_price, ‘> sum(total_lines) total_lines ‘> from demo.dashboard_customer_sales dsc ‘> group by customer_id ‘> order by total_price…) mysql> call flexviews.enable( -> flexviews.get_id(‘demo’,'dashboard_customer_sales’)); Query OK, 0 rows affected (41 min 52.04 sec) *If…
Post: Distributed Set Processing with Shard-Query
May 14, 2011 By 27 Comments
… of compute resource which speaks SQL, but right now only MySQL storage nodes are supported. Amdahl’s law applies to the… `sum(DepDelay)`, SUM(`sum(DepDelay >= 0) flight_delayed`) AS `sum(DepDelay >= 0) flight_delayed` FROM `aggregation_tmp_74082863` GROUP BY 1 –POST EXEC: DROP TABLE IF EXISTS…
Post: The case for getting rid of duplicate “sets”
May 17, 2011 By 2 Comments
….00 sec) mysql> select sum(val) from ex1; +———–+ | sum(val) | +———–+ | 871537665 | +———–+ 1 row in set (5.49 sec) Now, what if I structure my… table in the database by removing the duplicates: mysql> create table ex2 as select val, count(*) from ex1 group by val; Query OK, 9…
