…in software RAID 10. Now let’s come to the MySQL configuration. MySQL Configuration I used Percona Server 5.5…In this particular case, since I was mostly concerned with write performance, so I went ahead to choose a table…
Post: Multi Range Read (MRR) in MySQL 5.6 and MariaDB 5.5
March 21, 2012 By 10 Comments
…MySQL 5.5 MySQL 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…in MariaDB 5.5 and not in MySQL 5.6, is that because of a bug in MySQL 5.6 code? As MRR was used in both MySQL 5.6 and MariaDB 5.5…
Post: Join Optimizations in MySQL 5.6 and MariaDB 5.5
April 4, 2012 By 2 Comments
…available in both MySQL 5.6 and MariaDB 5.5. You can read more about BKA in MySQL 5.6 here and BKA in MariaDB 5.5 here. However, MariaDB 5.5 has…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 N/A N/A N/A 0 0 0 …
Post: Index Condition Pushdown in MySQL 5.6 and MariaDB 5.5 and its performance impact
March 12, 2012 By 12 Comments
… working with Peter in preparation for the talk comparing the optimizer enhancements in MySQL 5.6 and MariaDB 5.5. We are taking a look at and benchmarking optimizer enhancements one by one. So in the same… WHERE condition defined as: l_partkey = x and l_quantity >= 1 and l_quantity = 1 and l_quantity
Post: Troubleshooting MySQL Memory Usage
March 21, 2012 By 3 Comments
…MySQL to identify potential causes. Is it working with large blobs ? Using user variables ? Prepared Statements ? memory tables ? In a…1 row in set (0.00 sec) You can even go deeper to check which sessions have created which temporary tables (both in memory and not): mysql…
Post: Faster Point In Time Recovery with LVM2 Snaphots and Binary Logs
February 23, 2012 By Leave a Comment
…0 | +———-+ 1 row in set (0.00 sec) mysql> show tables; +———————+ | Tables_in_employees | +———————+ … | salaries | … +———————+ 6 rows in set (0.00 sec) So, as you can see, I now have a…
Post: InnoDB's gap locks
March 27, 2012 By 14 Comments
…a transaction, so there is no need to create locks to prevent that from happening. 2- innodb_locks_unsafe_for_binlog = 1…In the following link there is a good source of information: http://dev.mysql.com/doc/refman/5.1/en/innodb-locks-set.html. Conclusion MySQL…
Comment: InnoDB's gap locks
April 13, 2012 By 14 Comments
…mysql> show create table t\G *************************** 1. row *************************** Table: t Create Table: CREATE TABLE…1 | miguel | | 3 | andy | | 5 | aaron | | 8 | repls | +——+——–+ As I said, write queries behaves as if you were using READ COMMITTED in…
Post: Identifying the load with the help of pt-query-digest and Percona Server
December 29, 2011 By 3 Comments
…in MySQL…0 0 0 0 0 0 0 0 # Tmp tables 0 0 0 0 0 0 0 0 # Tmp disk tbl 0 0 0 0 0 0 0 0 # Tmp tbl size 0 0 0 0 0 0 0 0 # Query size 0 21.63k 71 71 71 71 0 71 # InnoDB: # IO r bytes 0 0 0 0 0 0 0 0…
Post: MySQL VIEW as performance troublemaker
August 12, 2007 By 53 Comments
… tables MySQL 5.0 will fail and perform very inefficiently in many counts. MySQL has two ways of handling the VIEWS – query merge, in… 0 | 850 | | 1 | 1790 | | 2 | 1777 | | 3 | 1762 | | 4 | 1784 | …. | 999 | 1808 | | 1000 | 898 | +———+——+ 1001 rows in set (0.96 sec) So now lets create a…
