… | 139448919 | 2735703 | +————+——–+———-+———–+———+ 10 rows in set (32.47 sec) MySQL mysql> select max(forum_id) as m,author_id as a from sptest… ,forum_id as f from sptest where num_links=1; Empty set (2.70 sec) MySQL mysql> select max(author_id) as a ,forum… cores and multiple nodes in the system. The raw scan speed was almost 10 millions of rows per second (this is…
Post: Why MySQL could be slow with large tables ?
June 9, 2006 By 141 Comments
…’ve been reading enough database related forums, mailing lists or blogs you probably heard complains about MySQL being unable to handle more… in random places – this may affect index scan/range scan speed dramatically. The rows referenced by indexes also could be located… large data sets. In MySQL single query runs as single thread (with exeption of MySQL Cluster) and MySQL issues IO requests one by…
Post: MySQL Query Cache
July 27, 2006 By 70 Comments
…called “Query Cache” which is quite helpful for MySQL Performance optimization tasks but there are number …- if you have high write application such as forums, query cache efficiency might be pretty low …of queries being cached this might reduce update speed a bit. Fragmentation over time – Over time …
Post: Implementing efficient counters with MySQL
July 1, 2007 By 16 Comments
…counter how many time given object – blog post, forum thread, image, movie etc was viewed. This is… but writes still have to happen at full speed. It also really hurts if you choose replication … use existing solutions you can use memcache + another mysql instance (or simply the database which is not …
Comment: To pack or not to pack - MyISAM Key compression
November 2, 2012 By 4 Comments
… the introduction of MySQL, saying it will be faster for reading, which is what we need in Discuz! Forum application. I do some small tests and find that the speed is not increasing(besides, in my database, maybe there is very few string indexes, the speed declining is also not obvious). Then I search and find…
Page: Presentations
May 3, 2006 By
…can speed up various things in MySQL as well as solve other performance related problems. Download Innodb Performance Optimization MySQL …and Performance Issues in MySQL MiracleAS Database Forum 2003, Denmark Presentation speaks about benchmarking issues and MySQL performance issues and settings….
Post: Possible optimization for sort_merge and UNION ORDER BY LIMIT
September 18, 2007 By 10 Comments
… – using UNION instead of single query works in this case: mysql> explain (select * from utest where c1=5) union (select * from… used for finding rows or sorting as well) but query speed goes to less than 0.01 sec. So it is… to do. P.S This post is inspired by Does MySQL Optimize UNION with LIMIT clause topic on our MySQL Forums.
Comment: MySQL Partitioning - can save you or kill you
June 28, 2012 By 45 Comments
…This discussion with Ashish should be on http://forums.mysql.com/list.php?24 ) > 8GB RAM > key_buffer_size=512M … would recommend (if you stick with MyISAM) 1500M. See http://mysql.rjweb.org/doc.php/memory For InnoDB, innodb_buffer_pool… your secondary keys; they are possibly useless. This will greatly speed up INSERTs. > PRIMARY KEY (`ObjectClass`, `ObjInstance`, `UTCTime`), Including a time…
Comment: Why MySQL could be slow with large tables ?
June 20, 2007 By 141 Comments
…set-variable=max_connections=1500 log_slow_queries=/var/log/mysql-slow.log sql-mode=TRADITIONAL concurrent_insert=2 low_…eking performance out of an InnoDB table for raw SELECT speed will take a committee of ten PhDs in RDBMS …this website is quite useful for people running the usual forums and such.
Comment: Innodb Performance Optimization Basics
November 1, 2007 By 75 Comments
…this site regularly and getting suggestions from the forums I’ve been able to consistently shave …down. working on it!) I’ve seen great speed improvements using just these tips alone. What …buffers and settings too high and restart your mysql server, mysql wont instantly complain. What I think happens…
