… to the MySQL configuration. MySQL Configuration I used Percona Server 5.5.22-55 for the tests. Following is the configuration that… = 4 innodb_file_per_table = 1 ## Disabling query cache query_cache_size = 0 query_cache_type = 0 You can see that the buffer… THAN MAXVALUE ENGINE = InnoDB) */ Also, I ran 5 instances of iiBench simultaneously to simulate 5 concurrent connections writing to the table, with…
Post: New distribution of random generator for sysbench - Zipf
May 9, 2012 By 3 Comments
… 3: 1,000,000/(2^1.1)=298,652 times, …, row id=10000 : 1,000,000/(10,000^1.1) = 39 times. Obviously with θ=0 we… row lookup 1 million times. There are histograms on how many times each row selected for different θ: 0.5, 0.9, 1.1: The curve is very skewed, so I zoomed graphs to show only 0-100k level: I…
Post: Testing Intel SSD 520
May 1, 2012 By 7 Comments
… synchronous IO varying amount of threads and with measurements every 1 sec to see how bad are drops. So there is… 5.5 uses async IO for writes. Maybe 8 threads in the first graph is too much and we should go with 1… !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id…
Post: Join Optimizations in MySQL 5.6 and MariaDB 5.5
April 4, 2012 By 2 Comments
… lowest query time is for MySQL 5.6 which takes 0.16s less as compared to MySQL 5.5 While with join_buffer_size… MariaDB 5.5 Hash Join Disabled w/ join_buffer_size=4M & mrr_buffer_size=4M Created_tmp_disk_tables 0 0 0 0 0 0 Created_tmp_tables 1 1 1 1 1 1 Handler_mrr_init N/A 112 3 1133 1 1 Handler_mrr_key_refills…
Post: Index Condition Pushdown in MySQL 5.6 and MariaDB 5.5 and its performance impact
March 12, 2012 By 12 Comments
… for the talk comparing the optimizer enhancements in MySQL 5.6 and MariaDB 5.5. We are taking a look at and benchmarking… Condition Pushdown (ICP). Its available in both MySQL 5.6 and MariaDB 5.5 Now let’s take a look briefly at what… WHERE condition defined as: l_partkey = x and l_quantity >= 1 and l_quantity = 1 and l_quantity
Post: Multi Range Read (MRR) in MySQL 5.6 and MariaDB 5.5
March 21, 2012 By 9 Comments
… 5.6 MySQL 5.6 w/ read_rnd_bufer_size=4M MariaDB 5.5 MariaDB 5.5 w/ mrr_buffer_size=4M Created_tmp_disk_tables 1 1 1 1 1 Created_tmp_tables 1 1 1 1 1 Handler_mrr_init N/A 0 0 1 1 Handler… Select_scan 1 1 1 1 1 Sort_scan 1 1 1 1 1 As you can see from the status counters above that both MySQL 5.6 and MariaDB 5.5 are…
Post: Percona Server 5.5.21-25.1 released!
March 29, 2012 By 8 Comments
… is glad to announce the release of Percona Server 5.5.21-25.1 on March 30, 2012 (Downloads are available here and… 5.5.21, including all the bug fixes in it, Percona Server 5.5.21-25.1 is now the current stable release in the 5.5…. Bugs Fixed: Fixed a memory corruption regression introduced in 5.5.18-23.0. Bug fixed #915814 (Alexey Kopytov). Fixed InnoDB compilation warnings…
Comment: How to replace a NDB node on EC2
February 22, 2012 By 10 Comments
…=4 @10.0.0.1 (mysql-5.1.56 ndb-7.1.13, Nodegroup: 0, Master) id=5 @10.0.0.3 (mysql-5.1.56 ndb-7.1.913 starting, Nodegroup: 0) ndb_mgm> all status; Node 4: started (mysql-5.1.56 ndb-7.1…
Post: Troubleshooting MySQL Memory Usage
March 21, 2012 By 3 Comments
…it is a lot larger problems with MySQL 5.5 with addition of user variables, stored procedures, prepared… +——————————-+ | sum(data_length+index_length) | +——————————-+ | 126984 | +——————————-+ 1 row in set (0.98 sec) This however will not …
Post: ext4 vs xfs on SSD
March 15, 2012 By 23 Comments
… to consider. Starting the MySQL 5.1 + InnoDB-plugin and later MySQL 5.5 (or equally Percona Server 5.1 and 5.5), InnoDB uses “asynchronous” IO in… is to another question I was asked, namely: “If MySQL 5.5 uses async IO, is innodb_write_io_threads still important… !function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0];if(!d.getElementById(id)){js=d.createElement(s);js.id…
