… MySQL has traditionally been challenging. Most data can be obtained from the slow or general log, but this involves a lot of data… is needed as the plugin needs the offset to some MySQL data structures that, the plugin authors say, aren’t exposed by…”:”debian-sys-maint”,”host”:”localhost”,”cmd”:”Connect”,”query”:”Connect”} {“msg-type“:”activity”,”date”:”1369155747373″,”thread-id”:”6439″,”query-id”:”219309″,”user…
Comment: Converting Character Sets
June 12, 2013 By 22 Comments
… correct. There was no truncation: MEDIUMTEXT is bigger than TEXT. MySQL does this to make sure there’s *no* truncation, as… – http://dev.mysql.com/doc/refman/5.1/en/alter-table.html “For a column that has a data type of VARCHAR or one of the TEXT types, CONVERT TO CHARACTER SET will change the data type as necessary to…
Post: MySQL and the SSB - Part 2 - MyISAM vs InnoDB low concurrency
May 22, 2013 By Leave a Comment
… Benchmark. In my previous blog post I compared MySQL 5.5.30 to MySQL 5.6.10, both with default settings using… different time periods or different regions. The flights represent the type of investigations and drill-downs that are common in OLAP… KEYS. my.cnf [mysqld] datadir=/mnt/mysql56/data basedir=/usr/local/mysql socket=/var/lib/mysql/mysql.sock user=justin innodb_buffer_pool_size…
Post: More on MySQL transaction descriptors optimization
April 26, 2013 By Leave a Comment
… away from this spherical read-only cow and throw some data updates into the mix, limitations of read-only transactions become…-type=uniform –forced-shutdown=1 –max-time=120 –max-requests=0 –percentile=99 –mysql-user=root –mysql-db=sbtest8t1M –mysql-table-engine=INNODB –mysql-socket…
Post: MySQL and Percona Server in LinkBench benchmark
May 8, 2013 By 18 Comments
…default linkbench dataset has 10M ids(after load of data size of datadir ~10GB). We used this dataset … Server 5.5 outperforms MySQL in about 2x times. Both MySQL 5.5.30 and MySQL 5.6.11 demonstrate …-cache=1000 query_cache_size=0 query_cache_type=0 performance_schema=0 #56only loose-innodb_flush_…
Post: High-load problems? Investigate them with 'pt-query-digest'
April 23, 2013 By 2 Comments
…. Granted, this means there is no run time data available, but at least you get a nice… timestamps) and ran that by pt-query-digest –type rawlog –report-format profile, to get just the…If you regularly work with MySQL databases, getting familiar with Percona Toolkit for MySQL will let you do more …
Post: How to recover table structure from InnoDB dictionary
April 22, 2013 By 4 Comments
… SYS_COLUMNS Table SYS_COLUMNS stores fields names and type information of the table. CREATE TABLE `SYS_COLUMNS`…tables into some MySQL server. Use LOAD DATA INFILE constraints_parser generates mysql>LOAD DATA INFILE ‘/path/to…
Post: Benchmarking Percona Server TokuDB vs InnoDB
May 7, 2013 By 32 Comments
…-rel30.2-500.Linux.x86_64/lib/mysql/libjemalloc.so [mysqld] gdb datadir=/mnt/data/mysql #for SSD innodb_flush_neighbor_pages = none innodb_adaptive_flushing_method = keep_average innodb_file_per_table = true innodb_data… query_cache_size = 0 query_cache_type = 0 ft_min_word_len = 4 #default_table_type = InnoDB thread_stack = 192K tmp_table…
Post: Virident vCache vs. FlashCache: Part 2
May 17, 2013 By 3 Comments
…second intervals. All tests were conducted with approximately 78GiB of data (32 tables, 10M rows each) and a 4GiB buffer …–rand-type=pareto \ –forced-shutdown=1 –max-time=7200 –max-requests=0 –percentile=95 \ –mysql-user=root –mysql-socket=/tmp/mysql.sock –mysql-table-…
Post: Wow. My 6 year old MySQL Bug is finally fixed in MySQL 5.6
August 30, 2012 By 2 Comments
…data types Make sure you’re using consistent data types…
