…: I should note MySQL 5.0 vs 4.1 has a lot …size=20480Mâ€) while the bulk of the rest (9 GB) is used for the OS cache…_size Q36: There have been several MySQL bugs opened about multi-core scalability (concurrent queries…on to quantify what are the limits of different operations for different levels…
Post: Heikki Tuuri Innodb answers - Part I
October 26, 2007 By 19 Comments
…size drops below this limit, merging it to a neighbor is tried */ #define BTR_CUR_PAGE_COMPRESS_LIMIT (UNIV_PAGE_SIZE…if they were not matched by query where clause when it was…it would write at 100MBps vs 33MBps. Any plans to enable… a battery-backed disk controller cache, then the commit returns in …
Comment: Full text search for all MySQL Storage Engines
June 28, 2006 By 37 Comments
… vectorbased storage regarding size needed on disk. Not only space needed is changed between using regular reversed index vs vectorbased storage but… to avoid hitting the query cache during tests): Reversed index without cheating: 24.0 seconds Reversed index with cheating (limit each word internally…
Post: MySQL Replication vs DRBD Battles
April 28, 2008 By 12 Comments
… meaning if your production database size growths load changes or … to two topics. First – hot vs cold. If you’re …and CPU cycles on double caching. Even in this case …same time as running reporting queries on last month. All last…hardware bugs rather than known limitations. You could argue depending …
Post: Just do the math!
July 6, 2009 By 4 Comments
…query like “SELECT page,count(*) cnt FROM logs GROUP BY page ORDER BY cnt DESC LIMIT… performance will change with data size, cardinality or other factors and … on other hand there is also caching which may be taking place. …Finally let me talk about modeling vs benchmarking for capacity planning. I’…
Post: Economics of Performance Optimization
March 13, 2008 By 9 Comments
… First lets talk about optimizing application vs getting better hardware. With … dramatically after certain hardware size. For example right now … If single user CPU bound query takes 30 seconds you …limited by MySQL server so the alternative would be either spend $5000 on implementing caching…
Post: Why MySQL could be slow with large tables ?
June 9, 2006 By 141 Comments
… is – depending if workload is cached or not different selectivity …The times for full table scan vs range scan by index: mysql>… problem is not the data size – normalized data normally becomes smaller…limitation which requires you to be extra careful working with large data sets. In MySQL single query…
