May 25, 2012

Post: Join Optimizations in MySQL 5.6 and MariaDB 5.5

… Name MySQL 5.5 MySQL 5.6 MySQL 5.6 w/ join_buffer_size=6M & read_rnd_buffer_size=6M MariaDB 5.5 MariaDB 5.5 w/ join_buffer_size=6M & mrr_buffer_size=6M MariaDB 5.5 Hash Join Disabled w/ join_buffer_size=4M & mrr_buffer_size

Post: Multi Range Read (MRR) in MySQL 5.6 and MariaDB 5.5

… variable read_rnd_buffer_size, while MariaDB introduces a different variable to control the MRR buffer size mrr_buffer_size. Both buffer sizes default to 256K in MySQL 5.6 and MariaDB 5.5…’ (only on MariaDB 5.5) optimizer_switch=’mrr_cost_based=off’ read_rnd_buffer_size=4M (only on MySQL 5.6) mrr_buffer_size=4M (only on MariaDB 5.5) We have…

Post: Index Condition Pushdown in MySQL 5.6 and MariaDB 5.5 and its performance impact

… preparation for the talk comparing the optimizer enhancements in MySQL 5.6 and MariaDB 5.5. We are taking a look at and benchmarking… Index Condition Pushdown (ICP). Its available in both MySQL 5.6 and MariaDB 5.5 Now let’s take a look briefly at what…

Post: MySQL Server Variables - SQL layer or Storage Engine specific.

read_buffer_size, read_rnd_buffer_size – Variables used as read buffer for MyISAM tables for Full Table Scan (read_buffer) and for reading rows in sorted order (read_rnd_buffer_size

Post: Shard-Query EC2 images available

…-64bit x86_64 Percona Server 5.5.11 with XtraDB. Requires m1….mysql-inno.sock [mysqld] socket=/tmp/mysql-inno.sock default-storage-engine=INNODB innodb-buffer-pool-instances=2 innodb-buffer-pool-size…=3306 read-buffer-size=512K read-rnd-buffer-size=1M skip-host-cache skip-name-resolve sort-buffer-size

Post: New SpecJAppServer results at MySQL and Sun.

… it better to disable them. The MySQL Settings are probably what is the most interesting: MySQL 5.0 Tuning in /etc/my.cnf…_cache = 6000 read_rnd_buffer_size = 2M sort_buffer_size = 32k thread_cache = 16 query_cache_size = 0M thread_concurrency = 8 max_heap_table_size=200M log-output…

Post: Are larger buffers always better ?

…and some 10 distinct c values. read_buffer_size and read_rnd_buffer_size – These are buffers used by MyISAM to perform reads, in different scenarios. So should …* FROM LARGETABLE LIMIT 5 MyISAM will allocate the buffer and populate if fully when MySQL will read only 5 rows from the buffer and throw …

Comment: MySQL Server Memory Usage

…, OS : Ubuntu server 11.04. I use Mysql server version 5.5. some table using engine MYISAM and …buffer_size = 2M read_buffer_size = 2M read_rnd_buffer_size = 8M myisam_sort_buffer_size = 64M thread_cache_size = 8 query_cache_size = 32M thread_concurrency = 8 log-bin=mysql-bin #innodb_buffer_pool_size

Comment: Database problems in MySQL/PHP Applications

… # The MySQL server [mysqld] port = 3306 socket = /tmp/mysql.sock bind-address=10.234.94.71 skip-locking key_buffer_size = 2000M …_buffer_size = 100M read_buffer_size = 100M read_rnd_buffer_size = 100M myisam_sort_buffer_size = 100M max_length_for_sort_data=2048 max_sort_length=2048 long-query-time=5

Comment: MySQL File System Fragmentation Benchmarks

size=100G myisam_max_extra_sort_file_size=100G myisam_sort_buffer_size=185M key_buffer_size=157M read_buffer_size=64K read_rnd_buffer_size=256K sort_buffer_size