June 20, 2013

Post: Implementing SchemaSpy in your MySQL environment

…don’t despair, you just have a bit more work ahead of you.  Most of the time SchemaSpy “does the … unsigned NOT NULL AUTO_INCREMENT, PRIMARY KEY (`parent_id`) ) ENGINE=InnoDB DEFAULT CHARSET=latin1 CREATE TABLE `child_A` ( `id` int(…?  Feel free to answer via the comments.  Thanks for reading!

Comment: MySQL and Percona Server in LinkBench benchmark

… this workload-hardware innodb_io_capacity = 20000 innodb_io_capacity_max = 100000 innodb_read_ahead_threshold = 0 innodb_change_buffer_max_size = 1 innodb_lru_scan_depth…

Post: More on MySQL transaction descriptors optimization

… the first two cases Percona Server performance is even slightly ahead of MySQL 5.6.10, but nothing unexpected. So while… innodb_buffer_pool_size = 52G innodb_log_file_size = 2000M innodb_log_files_in_group = 2 innodb_file_per_table = true innodb_read_io_threads = 8 innodb_write_io_threads = 8 innodb

Post: Can Innodb Read-Ahead reduce read performance ?

… non read ahead requests happening as well, at least 10 times more than number of read-ahead requests. May be it is poor read-ahead performance plus multiple threads doing scattered O_DIRECT (so no OS read-ahead) single page reads… in this project from MySQL AB side) – to improve how Innodb read-ahead works by having more overlap between requests so thread would…

Post: read_ahead (disabled) as steroid

… of “read_ahead“. And if in the same benchmark you disable read-ahead (innodb_read_ahead=none), you can see improvement about 15% Actually control of read_ahead is very simple patch and can easily be included in 5.4 or InnoDB-plugin. For curiosity… – in the same time gaps can be smoother with disabled read_ahead, however disabling it does not show such improvement like on…

Post: Effect from innodb log block size 4096 bytes

innodb_adaptive_checkpoint=keep_average innodb_thread_concurrency=0 innodb_flush_method = O_DIRECT innodb_read_ahead = none innodb_flush_neighbor_pages = 0 innodb_write_io_threads=16 innodb_read_io_threads=16 innodb

Post: Heikki Tuuri Innodb answers - Part I

… gets it wrong. Q10: When Innodb decides to schedule sequential read-ahead, random read ahead ? HT: InnoDB schedules a sequential read-ahead when it notices an ascending access… used for read ahead and results were significant. They however were not merged in Innodb mainline yet. Q11: If read-ahead is happening and Innodb needs…

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

… 136163 136435 Innodb_buffer_pool_read_ahead 0 20920 23669 20920 23734 Innodb_buffer_pool_read_requests 1361851 1264739 1235472 1263290 1235781 Innodb_buffer_pool_reads 120548 102948 76882 102672 76832 Innodb

Post: Heikki Tuuri answers to Innodb questions, Part II

… one read-ahead can happen at the same time. How many read-aheads can be waiting in Queue when or Innodb will schedule more read-aheads only when given read-ahead is completed? HT…

Post: The performance effects of new patches

…. innodb_read_ahead (default 3) This controls [enable/disable] of read-ahead. 3: normal 2: enable linear read-ahead only 1: enable random read-ahead only 0: disable both innodb… the performance. * This test uses “innodb_read_ahead = 0″ (The both of read-ahead are disabled) “innodb_ibuf_contract_const = 50000″ “innodb_ibuf_contract_burst = 50000″ (For…