… Intel 320 I would say is the most popular. I do not particularly like its write performance – I wrote about it before… is primary usage for me), and recently I switched to use async IO mode. There are two reasons for that. First… 1.62ms under 32 threads. The periodic drops that I observe for both random reads and random writes do not allow me to…
Post: Load management Techniques for MySQL
May 6, 2012 By 2 Comments
… side load so it does not consume too much system resources. Here are some specific techniques to use. Do push concurrency too high Many developers will test script with multiple level of concurrency and find out doing work from 32… to where it does not overload the system. Unless it is really time critical process I would not use more than 4 parallel…
Post: Introducing new type of benchmark
February 25, 2012 By 16 Comments
…that we pioneered (not invented, but started to use widely) a benchmark methodology when we measure not the final…will it help to improve the response time ? – Do we need to increase number of working … with 1579.91ms final. That means that 16-32 threads is probably best number of concurrently working…
Post: Do you always need index on WHERE column ?
August 28, 2007 By 16 Comments
…` ( `id` int(10) unsigned NOT NULL auto_increment, `name` varchar(32) NOT NULL, `has_something` tinyint(3) unsigned NOT NULL, PRIMARY KEY (`id`), KEY….5 times slower. Good that mysql in this case choose do not use index mysql> explain select count(name) from testr where has… | 1 | SIMPLE | testr | ALL | has_something | NULL | NULL | NULL | 15000000 | Using where | +—-+————-+——-+——+—————+——+———+——+———-+————-+ 1 row in set (0.00 sec) Let look…
Post: To UUID or not to UUID ?
March 13, 2007 By 28 Comments
… at the benchmark – we do not have full schema specified in the article itself so it results are not absolutely clear but we… tree not fitting into memory. This is not simply the case of 32 bytes vs 4 bytes for key value – if you would use… case, it will be misleading more frequently than not, especially if you do not have technical depth to understand all implications and assumptions…
Post: Flexviews - part 3 - improving query performance using materialized views
April 4, 2011 By 12 Comments
…and maintain the view. You should always use the stored procedures to modify the dictionary. Do not modify it directly. convert.php You…order_lines\G *************************** 1. row *************************** cnt: 155187034 1 row in set (32.03 sec) mysql> select sum(total_lines) cnt from …
Post: Getting around optimizer limitations with an IN() list
January 9, 2010 By 9 Comments
… feature of the MySQL optimizer – and it has to do with using x BETWEEN 30 and 40 (and it’s also true…,30.61,31.18,31.26,31.72,32.11,32.25,32.30,32.42,32.91,33.27, 33.69,33.79,33… that we can use for indexes: ALTER TABLE coordinates ADD x_floor INT NOT NULL, ADD y_floor INT NOT NULL, DROP INDEX…
Post: Testing the Group Commit Fix
July 13, 2011 By 13 Comments
…_binlog=1 and you do not have storage that provides fast syncs (i.e. you do not have a battery-backed cache…13 In this case, there is no improvement when using the fix. In order to summarize: the fix improves…84 3829.70 3859.48 256 2877.98 2145.32 2188.38 There is still performance difference binlogs …
Post: Aligning IO on a hard disk RAID – the Benchmarks
June 9, 2011 By 11 Comments
…-tables Amount of rows used was 20M, transactions were not used (autocommit), number of threads – 1, 4, 8, 16 and 32. Benchmark scenarios Here…, Ubuntu 10.04 and similar systems if you wouldn’t do anything with respect to IO alignment yourself. In this case… be able to fix that (not verified). 6. Added LVM on top of aligned partition table, used proper file system alignment. Benchmark…
Comment: Integers in PHP, running with scissors, and portability
April 6, 2007 By 32 Comments
… value (that’s 32 bits signed). PHP does not support unsigned integers.” You will also run into problems when doing bit shifting operations… which may give you different results on 32 and 64 bit machines if you do not reformat its results with dechex or sprintf… values serialized on 64 bit systems on 32 bit systems. Imagine using a mixed environment with 32 and 64 bit servers that need…
