…allocated from OS you might not see “VSZ” going down. What you might see instead is flushing tables regularly or reducing… *************************** 1. row *************************** SESSION_ID: 7234 TABLE_SCHEMA: test TABLE_NAME: my ENGINE: InnoDB NAME: #sql516_1c42_2 TABLE_ROWS: 0 AVG_ROW_LENGTH…
Post: Multi Range Read (MRR) in MySQL 5.6 and MariaDB 5.5
March 21, 2012 By 10 Comments
… Now let’s take a look at what this optimization actually is and what benefits it brings. Multi Range Read … n_nationkey group by c_custkey, c_name, c_acctbal, c_phone, n_name, c_address, c_comment order by revenue… to cover it here, but will cover it in my next post which will be on Block Access Join…
Post: ext4 vs xfs on SSD
March 15, 2012 By 23 Comments
… for example Domas’s post) However from the results of my recent benchmarks I felt that this should be revisited. While… earlier results what I have. I use STEC SSD drive 200GB SLC SATA (my thanks to STEC for providing drives). What I see… result significantly. This is to another question I was asked, namely: “If MySQL 5.5 uses async IO, is innodb_write…
Post: Join Optimizations in MySQL 5.6 and MariaDB 5.5
April 4, 2012 By 2 Comments
…uses Nested Loop Join to join two or more tables. What this means is that, select rows from first table …engine then uses the MRR interface (which I explained in my previous post) to lookup the rows in table2. So …let’s take a look at the status counters. Counter Name MySQL 5.5 MySQL 5.6 MySQL 5.6 …
Comment: Avoiding auto-increment holes on InnoDB with INSERT IGNORE
March 11, 2012 By 7 Comments
… problem. 1. You have to add one row to your my.ini file. # =0 is traditional lock mode == > funcionality of auto… investigate what it do innodb_autoinc_lock_mode=0 2. restart mysql server now is working perfectly id – is primary key name – is unique varchar insert into tab (name) values (‘Peter’),(‘Oto’),(‘Jan’),(‘Jan’),(‘Jan’),(‘Romco…
Post: Index Condition Pushdown in MySQL 5.6 and MariaDB 5.5 and its performance impact
March 12, 2012 By 12 Comments
… Now let’s take a look briefly at what this enhancement actually is, and what is it aimed at. Index Condition Pushdown…
Comment: Btw xtrabackup is not only backup..
March 5, 2012 By 12 Comments
… ALL privileges on the database. My “WTF directory” is directed toward the fact that the message names at least four directories in… no one bothered to even give him a tip about what directory. Also, there are several documented bugs in the Percona… fixed or if it’s simply a problem with documentation. What I DO know is that I’m here to design…
Comment: Too many connections? No problem!
March 15, 2012 By 28 Comments
…; I have my website develop in PHP with MYSQL, these are MYSQL …connections = 600 wait_timeout = 60 interactive_timeout=1800 skip-name-resolve skip-bdb default-time-zone=America/Caracas …an attack, will have any suggestions or ideas of what might be causing thereby increase the number of connections…
Post: Enum Fields VS Varchar VS Int + Joined table: What is Faster?
January 24, 2008 By 27 Comments
…` tinyint(3) NOT NULL auto_increment, `name` char(40) NOT NULL, PRIMARY KEY (`id`), UNIQUE KEY `name` (`name`) ) ENGINE=MyISAM; All cities_* tables… select_type: SIMPLE table: s type: const possible_keys: PRIMARY,name key: name key_len: 40 ref: const rows: 1 Extra: *************************** 2… querying state by ID. Next test was a result of my curiosity. I’ve tried to order results by states. 1…
Post: Cache Performance Comparison
August 9, 2006 By 73 Comments
… cache usage efficiency larger object size and other reason. So what my test does ? Simply we perform 10.000 of get requests… result sets are cached from query cache. Pretty impressive. So what my recommendations would be about using these caches for your application… requirements: 1) for file cache to work you need file named “test” containing “MyTestString” 2) You need to create table test…
