…select flexviews.get_sql( -> flexviews.get_id(‘demo’,'dashboard_customer_sales’)) -> as ‘SQL‘ \G *************************** 1. row *************************** SQL: SELECT…
Post: Flexviews - part 3 - improving query performance using materialized views
April 4, 2011 By 20 Comments
Post: Shard-Query adds parallelism to queries
November 15, 2010 By 18 Comments
… Then I hit upon the idea of taking SQL constructs like IN and BETWEEN and making these…collected flight data. For example (the final query): select count(*) from ontime.ontime where FlightDate BETWEEN ’1988…word-spacing:0;background-color:#fff;z-index:1;border-top:0px none;border-left:0px none;border…
Post: Using GROUP BY WITH ROLLUP for Reporting Performance Optimization
September 17, 2007 By 14 Comments
… interested in best selling product or top sales people. This information may often need simple select query, however what if you would… slack like “a%” group by grp with rollup \G *************************** 1. row *************************** id: 1 select_type: SIMPLE table: dt type: ALL possible_keys: NULL… filesort 1 row in set (0.00 sec) As I forced FileSort execution method for GROUP BY by using SQL_BIG_RESULT…
Comment: MySQL Server Memory Usage
September 1, 2006 By 21 Comments
…’, ’0′ ‘Com_preload_keys’, ’0′ ‘Com_prepare_sql‘, ’0′ ‘Com_purge’, ’0′ ‘Com_purge_before_…status’, ‘NULL’ ‘Select_full_join’, ’0′ ‘Select_full_range_join’, ’0′ ‘Select_range’, ’5683551′ ‘Select_range_check’, ’0′ ‘Select_scan’,… ’4433556′ # top 18:38:40 up 175 days, 2:56, 1 user, load average: 0.79, 1…
Post: Innodb performance gotcha w Larger queries.
August 28, 2009 By 7 Comments
…INSERT ON DUPLICATE KEY UPDATE) As I went from 1 value to 3 or 10 in the batch …- not the function you would expect to see on top for update workload ! I asked Yasufumi, our Innodb code…whether the SQL is “SELECT” or not. 5.0 does scanning the SQL for each time. if (trx->isolation_level select_lock…
Post: Quick comparison of MyISAM, Infobright, and MonetDB
September 29, 2009 By 30 Comments
… doing was loading the data with SQL statements. I wanted to see how … Infobright, anyway. The tests I loaded 1 million rows into the table. Here…ran three queries: select sum(c19), sum(c89), sum(c129) from t; select sum(c19), …() statements). What did I see in ‘top‘ but a program called bhloader. This…
Post: High-Performance Click Analysis with MySQL
December 22, 2008 By 13 Comments
… Clicks by day, by customer, top ads by clicks, top ads by click-through ratio, … so ETL jobs written to rely on SQL tend to get really bogged down. …advance. What about partitioning in MySQL 5.1? I know there are some … do it on the master with INSERT..SELECT queries, it will propagate to the …
Post: MySQL Slow query log in the table
May 31, 2007 By 1 Comment
… of MySQL 5.1 get MySQL slow query log logged in mysql.slow_log … to SELECT * FROM slow_log ORDER BY start_time DESC LIMIT 100 you would find new queries coming to the top of… placeholders as this would allow to aggregate log entirely in SQL finding most frequent slow query types or queries which load…
Post: CVE-2012-4414 strikes back in MySQL 5.5.29 (and what we're doing in Percona Server 5.5.29)
January 13, 2013 By 4 Comments
… okay or not which typically includes a few patches on top of the base distribution. Sadly, Oracle did not run the… line 1‘ on query. Default database: ‘db1`; SELECT ‘oops!”. Query: ‘LOAD DATA INFILE ‘../../tmp/SQL_LOAD-2-1-1.data’ INTO TABLE `t“1` FIELDS TERMINATED BY ‘,’ ENCLOSED BY ‘\” ESCAPED BY ‘\\’ LINES TERMINATED BY ‘\n’ (`a“1`, @b…
