I have been working with Peter in preparation for the talk comparing the optimizer enhancements in MySQL 5.6 and MariaDB 5.5. We are taking a look at and benchmarking optimizer enhancements one by one. So in… new optimizer enhancement Index Condition Pushdown (ICP). Its available in both MySQL 5.6 and MariaDB 5.5 Now let’s take…
Post: Index Condition Pushdown in MySQL 5.6 and MariaDB 5.5 and its performance impact
March 12, 2012 By 12 Comments
Post: How Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
…tables and Created_disk_tmp_tables, I’ll paste in mysql> show global variables like ‘%table_size%’; +———————+———–+ | Variable_name | Value | +———————+———–+ | max_heap_table_size | 268435456 | | tmp_table…how much total gain I can get from it. Queries…
Post: The case for getting rid of duplicate “sets”
May 17, 2011 By 2 Comments
…data differently? We can “compress” the table in the database by removing the duplicates: mysql> create table ex2 as select val, count(*) from ex1 group by val; Query…
Post: High-Performance Click Analysis with MySQL
December 22, 2008 By 13 Comments
…search engine marketing. I’ll do that throughout this article. Requirements The words “need” and “want” are different…tables in a complex query with many joins. I have never seen this approach scale well. Use The Best Technologies You Can MySQL…
Post: Why you should ignore MySQL's key cache hit ratio
February 28, 2010 By 27 Comments
…difference between “rate” and “ratio”. In…from the standpoint of response time measurements, which you should, you will eventually arrive at this question. “I have a query…how important those tables are to you, how…in MySQL to guide your decisions. It is also not the be-all and end-all of MySQL…
Post: Why MySQL could be slow with large tables ?
June 9, 2006 By 139 Comments
…data fits in memory and when it does not are very different. If you started from in-memory data…data sets. In MySQL single query runs as single thread (with exeption of MySQL Cluster) and MySQL issues IO requests one by one for query…
Post: SHOW INNODB STATUS walk through
July 17, 2006 By 40 Comments
…mysql tables in use 1, locked 0 MySQL thread id 8079, query id 728899 localhost root Sending data select sql_calc_found_rows * from…search with hash search. This section shows hash table…how much data is unflushed in…in time. Different lines in SHOW INNODB STATUS populated in different point in…
Post: Heikki Tuuri Innodb answers - Part I
October 26, 2007 By 17 Comments
…from using a binary search on a B-tree node. We could not compare a search…how your data will compress for the whole table. Among other things compression for data pages and uncompressed index pages can be significantly different…in MySQL 5.1 Q15: How…
Post: Heikki Tuuri answers to Innodb questions, Part II
November 4, 2007 By 13 Comments
…How many read-aheads can be waiting in…data access distribution gains will be different ranging from…MySQL bugs opened about multi-core scalability (concurrent queries…table size 10624987, used cells 1, node heap has 1 buffer(s) 0.00 hash searches/s, 15979.01 non-hash searches…
Post: Goal driven performance optimization
December 22, 2008 By Leave a Comment
…different response time guidelines for pages which are requested for real humans vs search engine bots (which are often quite different in…data in your work. For small and medium size applications you can log all requests to MySQL table…
