… not expect it to beat MySQLi in speed. It is however bad idea to use mysql_ functions directly as well – I would… your data however it does not always bring good performance. Joins are expensive and you can often do much better with… should rather be called Not using Join. This is typical error. On other hand in MySQL you might be better of using…
Post: TPC-H Run on MySQL 5.1 and 6.0
April 10, 2008 By 16 Comments
… and MySQL 6.0 can complete all queries within an hour. We can also see MySQL 6.0 improving query 20 speed dramatically, the rest of the queries is however close and MySQL 6.0… as surprised by these results – MySQL 6.0 still does not have hash or merge join which are frequently used for these…
Post: How to recover deleted rows from an InnoDB Tablespace
February 20, 2012 By 4 Comments
…-14 13:10:08 ETA(in 00:00 hours). Processing speed: 104857600 B/sec All pages are stored in a single… and types. mysql (information_schema) > select i.INDEX_ID, i.NAME FROM INNODB_SYS_INDEXES as i INNER JOIN INNODB_SYS_TABLES….01 sec) Records: 3 Deleted: 0 Skipped: 0 Warnings: 0 mysql (employees) > select * from salaries where emp_no=10008; +——–+——–+————+————+ | emp_no…
Comment: Multi Column indexes vs Index Merge
October 20, 2009 By 31 Comments
… results for a vehicle. Tried (date_time,vehicle_id) and MYSQL won’t use it, (date_time) and its bringing back… to 100 per second. Query select g.date_time, g.speed, g.odometer, gl.building_number_name, gl.street, gl.town…_moving, o.id as over_speed, l.name as location_name from gps_positions g inner join geocoded_locations gl on g…
Comment: Database problems in MySQL/PHP Applications
August 11, 2006 By 13 Comments
… not > expect it to beat MySQLi in speed. It is however bad idea to use > mysql_ functions directly as well – I would… should rather be called Not using > Join. This is typical error. On other hand in MySQL you might be > better of using… because it allows the optimizer to use the indexes to join rows together, potentially preventing a table scan. The trick is…
Post: Just do the math!
July 6, 2009 By 4 Comments
… predict it without running benchmarks. There are couple of ways MySQL may execute query above but lest focus on the most… on disk which affects scan speed. Another aspect is the temporary table – the number of rows MySQL can insert/update depends on… have more “random” access patterns – some form of index accesses, joins etc may be slowed down 100-1000 then going from…
Comment: Introducing new type of benchmark
February 25, 2012 By 16 Comments
… be used. Your tpcc-mysql for example doesn’t use JOINs, something we know is expensive in the MySQL world, yet Oracle and to some extent SQL Server handle better. JOIN has long been something MySQL has done… benchmark joins because they’re slow and we avoid them in the real world, so they don’t do anything to speed…
Comment: MySQL VIEW as performance troublemaker
January 4, 2010 By 57 Comments
… and its speed is turtle-fast (sarcasm, hehe). The EXPLAIN convinces me that temporary tables are being built and then joined. However… before doing the joins, adding the appropriate indexes, and still get horrible performance – it probably is more MySQL‘s join that is failing…
Comment: Enum Fields VS Varchar VS Int + Joined table: What is Faster?
July 7, 2008 By 30 Comments
… on the cities_join table. though I read something about frequent inserts with indexes being slow. but would indexing speed things up? and also SELECT SQL_NO_CACHE c.city FROM states s LEFT JOIN cities_join c ON… by state maybe if you place it at the left mysql would search for that first and then search for the…
Post: Heikki Tuuri Innodb answers - Part I
October 26, 2007 By 19 Comments
… so that we can see the full write speed of the disk for throughput. INNODB uses fuzzy …throughput? HT: ha_innodb.cc in 5.1: static MYSQL_SYSVAR_ULONG(thread_concurrency, srv_thread_concurrency, PLUGIN_… (for example, if ORDER and ORDERLINE tables are joined to form a single table), it might make …
