… of results for a vehicle. Tried (date_time,vehicle_id) and MYSQL won’t use it, (date_time) and its bringing back thousands of rows under explain. Using innodb. Inserting up to 100 per second. Query select g.date_time, g.speed, g.odometer, gl.building_number_name, gl.street, gl…
Post: MySQL 5.6 vs MySQL 5.5 and the Star Schema Benchmark
March 11, 2013 By 7 Comments
… 13 queries. I then repeated the run three more times. The speed is very consistent, just a few tenths of a second… innodb_old_blocks_time=0: mysql> select straight_join sum(lo_extendedprice*lo_discount) as revenue from dim_date join lineorder on… TABLE IF EXISTS dim_date; CREATE TABLE IF NOT EXISTS dim_date ( D_DateKey int primary key, D_Date char(18), D_DayOfWeek…
Post: MySQL Indexing Best Practices: Webinar Questions Followup
August 16, 2012 By 4 Comments
… on vendor, will the index have any impact on the speed of the query? A: If you extend the index from… time“, computing aggregate functions as needed. Q: Is there any special concerns or tricks for selecting using some date ranges? or between dates? or after a date? A: Date comparisons work very similar to other…
Post: How to recover deleted rows from an InnoDB Tablespace
February 20, 2012 By 4 Comments
…backup in order to save time and make the recovery process …(in 00:00 hours). Processing speed: 104857600 B/sec All pages…_no=10008; +——–+——–+————+————+ | emp_no | salary | from_date | to_date | +——–+——–+————+————+ | 10008 | 46671 | 1998-03-11 | 1999…
Post: Goal driven performance optimization
December 22, 2008 By Leave a Comment
… response time in average even speeding it up 10 times we would not get more than 10% response time reduction. At the same time if we find a way to speed up Sphinx we can reduce response time to its… above for example: mysql> select date_format(logged,’%H’) h,count(*),avg(wtime),avg(sphinx_time/wtime) sphinx_ratio from performance_log…
Comment: 3 ways MySQL uses indexes
July 20, 2010 By 28 Comments
… AND tree_type = “2220″ AND date_from = “0000-00-00″ AND date_to > “2010-06-01″ AND date_to <= "9999-12-31" AND... is used. KEY `type_from_to_vector` (`tree_type`,`date_to`,`date_from`,`tree_vector`) more in Slovak language : http://kyberia.sk… multiple range lookups with speeds in miliseconds. It’s maybe difficult to make it work the first time, to make the correct…
Post: How Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
… and we need to know ahead of time so we don’t spend time on things you have no way to … about the server I start off with these commands: date uname -a cat /etc/*release The first command is …what they are, both in terms of size and spindle speed. I need to know how many physical spindles are …
Post: To UUID or not to UUID ?
March 13, 2007 By 28 Comments
… short integer keys because they can become many times longer. Parallel Inserts UUID are often advertised as… constantly hitting, this is true but at large date size it is way overturned by BTREE buffer…. of benchmarks was rather lookup by primary key speed. Lookup speed can be similar or can vary a …
Post: Visualization tools for pt-query-digest tables
August 31, 2012 By 6 Comments
…that have first been seen since the specified date or date range. Also you can explain queries, see…instrument in a weather station that measures wind speed. SQL queries are like the wind — ephemeral and…to optimize and how to track performance over time. Anemometer relies on the Percona Toolkit to …
Post: Realtime stats to pay attention to in Percona XtraDB Cluster and Galera
November 26, 2012 By 4 Comments
… to keep my myq_gadgets toolkit up to date with what I consider is important to …paused — This is the amount of time since the last time SHOW GLOBAL STATUS was run that …if multi-threaded replication could help improve replication speed at all. Conflct Replication conflicts, as described in…
