…interested in best selling product or top sales people. This information may often…mysql> select grp, count(*) cnt from dt where slack like “a%” group by grp order by cnt desc limit 10; +——+—–+… for GROUP BY by using SQL_BIG_RESULT hint I can see GROUP BY executing about same time as GROUP BY…
Post: Using GROUP BY WITH ROLLUP for Reporting Performance Optimization
September 17, 2007 By 12 Comments
Post: Top 5 Wishes for MySQL
June 29, 2007 By 10 Comments
… have much support from MySQL to do so. What is really bad is Parallel query. Reporting with group by over 10.000.000 of… Oracle/DB2/MS SQL Queries on MySQL because subqueries optimizer weakness. I’m saying about XA which were released in MySQL 5.0 without consistent work with MySQL close Partner – Innobase to ensure Group Commit still works in…
Post: Flexviews - part 3 - improving query performance using materialized views
April 4, 2011 By 12 Comments
…group by customer_id, customer_name, sale_when; $ php convert.php demo < sales.sql…mysql> select flexviews.get_sql( -> flexviews.get_id(‘demo’,'dashboard_customer_sales’)) -> as ‘SQL‘ \G *************************** 1. row *************************** SQL…(dashboard_top_customers) to list the top 10 …
Post: Shard-Query adds parallelism to queries
November 15, 2010 By 16 Comments
…;text-indent:0px;padding-left:3px;border-top:1px solid #CCC;border-right:1px solid …31′ GROUP BY Origin ORDER BY c DESC LIMIT 10; Q4 – SELECT carrier, count(*) FROM ontime WHERE DepDelay>10 AND FlightDate… runs significantly faster than just running the SQL via MySQL. The remainder of Vadim’s queries …
Post: Is it query which needs to be optimized ?
March 6, 2007 By 9 Comments
…GROUP BY Consider SELECT COUNT(*) cnt, page FROM log GROUP BY page ORDER BY cnt DESC limit 10, the query to display top…group by so for large number of rows you’ve simply got to use different solutions, such as summary table. With MySQL… pretty inefficient. There is surely SQL_CALC_FOUND_ROWS but it…
Comment: Full text search for all MySQL Storage Engines
June 28, 2006 By 37 Comments
… 500.000 items of each word to process, group by, order by and so forth until the engine can spit out … items per word down to say 10 * endresult, like if you will return top 200 back to the client the …10 most common words found in the database, linux 2.6 and mysql 4.1.18 was used in all cases – SQL…
Post: Are you designing IO bound or CPU bound application ?
December 20, 2006 By 10 Comments
…is extremely important for MySQL Performance Optimization. In fact…taking at least 5-10 second, or more …group by, order by without indexes, search queries etc. Basically as soon as you have more than 100 rows analyzed by…_id=134 or use SQL_CALC_FOUND_ROWS flag …form of caching on top of that. For IO…
