I’ve never been a very big fan of MyISAM; I would argue that in most situations, any possible advantages to using MyISAM are far outweighed by the potential disadvantages and the strengths of InnoDB. However, up until MySQL 5.6, MyISAM was the only storage engine with support for full-text search (FTS). And I’ve encountered many [...]
Percona Server on the Raspberry Pi: Your own MySQL Database Server for Under $80
There are many reasons for wanting a small MySQL database server: You’re a uni student who wants to learn the SQL language better and needs a mini-testbox You’re a Windows user who wants to play around with Percona Server on Linux You’re a corporate application developer who wants a small SQL development & test box [...]
MySQL 5.5 and MySQL 5.6 default variable values differences
As the part of analyzing surprising MySQL 5.5 vs MySQL 5.6 performance results I’ve been looking at changes to default variable values. To do that I’ve loaded the values from MySQL 5.5.30 and MySQL 5.6.10 to the different tables and ran the query:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 | mysql [localhost] {msandbox} (test) > select var55.variable_name,left(var55.variable_value,40) value55, left(var56.variable_value,40) var56 from var55 left join var56 on var55.variable_name=var56.variable_name where var55.variable_value!=var56.variable_value; +---------------------------------------------------+------------------------------------------+------------------------------------------+ | variable_name | value55 | var56 | +---------------------------------------------------+------------------------------------------+------------------------------------------+ | PERFORMANCE_SCHEMA | OFF | ON | | PID_FILE | /mnt/data/sandboxes/msb_5_5_30/data/mysq | /mnt/data/sandboxes/msb_5_6_10/data/mysq | | CHARACTER_SETS_DIR | /mnt/nfs/dist/mysql-5.5.30-linux2.6-x86_ | /mnt/nfs/dist/mysql-5.6.10-linux-glibc2. | | PERFORMANCE_SCHEMA_MAX_COND_INSTANCES | 1000 | 836 | | PERFORMANCE_SCHEMA_MAX_MUTEX_INSTANCES | 1000000 | 3282 | | OLD_PASSWORDS | OFF | 0 | | INNODB_STATS_ON_METADATA | ON | OFF | | PERFORMANCE_SCHEMA_EVENTS_WAITS_HISTORY_SIZE | 10 | 5 | | PERFORMANCE_SCHEMA_EVENTS_WAITS_HISTORY_LONG_SIZE | 10000 | 100 | | PERFORMANCE_SCHEMA_MAX_RWLOCK_INSTANCES | 1000000 | 1724 | | PERFORMANCE_SCHEMA_MAX_TABLE_HANDLES | 100000 | 2223 | | INNODB_LOG_FILE_SIZE | 5242880 | 50331648 | | BASEDIR | /mnt/nfs/dist/5.5.30 | /mnt/nfs/dist/5.6.10 | | BACK_LOG | 50 | 80 | | OPEN_FILES_LIMIT | 1024 | 5000 | | INNODB_AUTOEXTEND_INCREMENT | 8 | 64 | | MAX_CONNECT_ERRORS | 10 | 100 | | SORT_BUFFER_SIZE | 2097152 | 262144 | | LC_MESSAGES_DIR | /mnt/nfs/dist/mysql-5.5.30-linux2.6-x86_ | /mnt/nfs/dist/mysql-5.6.10-linux-glibc2. | | MAX_ALLOWED_PACKET | 1048576 | 4194304 | | JOIN_BUFFER_SIZE | 131072 | 262144 | | TMPDIR | /mnt/data/sandboxes/msb_5_5_30/tmp | /mnt/data/sandboxes/msb_5_6_10/tmp | | TABLE_OPEN_CACHE | 400 | 2000 | | INNODB_VERSION | 5.5.30 | 1.2.10 | | INNODB_BUFFER_POOL_INSTANCES | 1 | 8 | | QUERY_CACHE_SIZE | 0 | 1048576 | | SLOW_QUERY_LOG_FILE | /mnt/data/sandboxes/msb_5_5_30/data/dpe0 | /mnt/data/sandboxes/msb_5_6_10/data/dpe0 | | TABLE_DEFINITION_CACHE | 400 | 1400 | | PORT | 5530 | 5610 | | QUERY_CACHE_TYPE | ON | OFF | | REPORT_PORT | 5530 | 5610 | | PERFORMANCE_SCHEMA_MAX_FILE_INSTANCES | 10000 | 1556 | | SQL_MODE | | NO_ENGINE_SUBSTITUTION | | INNODB_OLD_BLOCKS_TIME | 0 | 1000 | | LOG_ERROR | /mnt/data/sandboxes/msb_5_5_30/data/msan | /mnt/data/sandboxes/msb_5_6_10/data/msan | | VERSION_COMPILE_OS | linux2.6 | linux-glibc2.5 | | THREAD_CACHE_SIZE | 0 | 9 | | PLUGIN_DIR | /mnt/nfs/dist/5.5.30/lib/plugin/ | /mnt/nfs/dist/5.6.10/lib/plugin/ | | SYNC_RELAY_LOG | 0 | 10000 | | GENERAL_LOG_FILE | /mnt/data/sandboxes/msb_5_5_30/data/dpe0 | /mnt/data/sandboxes/msb_5_6_10/data/dpe0 | | PERFORMANCE_SCHEMA_MAX_TABLE_INSTANCES | 50000 | 445 | | SYNC_RELAY_LOG_INFO | 0 | 10000 | | SLAVE_LOAD_TMPDIR | /mnt/data/sandboxes/msb_5_5_30/tmp | /mnt/data/sandboxes/msb_5_6_10/tmp | | SECURE_AUTH | OFF | ON | | VERSION | 5.5.30 | 5.6.10 | | INNODB_CONCURRENCY_TICKETS | 500 | 5000 | | INNODB_PURGE_THREADS | 0 | 1 | | INNODB_OPEN_FILES | 300 | 2000 | | INNODB_DATA_FILE_PATH | ibdata1:10M:autoextend | ibdata1:12M:autoextend | | INNODB_PURGE_BATCH_SIZE | 20 | 300 | | PERFORMANCE_SCHEMA_MAX_THREAD_INSTANCES | 1000 | 224 | | SOCKET | /tmp/mysql_sandbox5530.sock | /tmp/mysql_sandbox5610.sock | | INNODB_FILE_PER_TABLE | OFF | ON | | SYNC_MASTER_INFO | 0 | 10000 | | DATADIR | /mnt/data/sandboxes/msb_5_5_30/data/ | /mnt/data/sandboxes/msb_5_6_10/data/ | | OPTIMIZER_SWITCH | index_merge=on,index_merge_union=on,inde | index_merge=on,index_merge_union=on,inde | +---------------------------------------------------+------------------------------------------+------------------------------------------+ 56 rows in set (0.05 sec) |
Lets go over to see what are the most important changes [...]
Adventures in archiving
One of our Remote DBA service clients recently had an issue with size on disk for a particular table; in short this table was some 25 million rows of application audit data with an on disk size of 345GB recorded solely for the purposes of debugging which may or may not occur. Faced with the task of [...]
Fun with the MySQL pager command
Last time I wrote about a few tips that can make you more efficient when using the command line on Unix. Today I want to focus more on pager. The most common usage of pager is to set it to a Unix pager such as less. It can be very useful to view the result [...]
Percona and the MariaDB Foundation
There have been several reports (1,2,3) describing Percona’s stance regarding the MariaDB Foundation that are not totally accurate so I though it would be worth it to describe where we stand on this and related matters. First, let me say the creation of theMariaDB Foundation is a good thing for the MariaDB Community and I’m [...]
Edge-case behavior of INSERT…ODKU
A few weeks back, I was working on a customer issue wherein they were observing database performance that dropped through the floor (to the point of an outage) roughly every 4 weeks or so. Nothing special about the environment, the hardware, or the queries; really, the majority of the database was a single table with [...]
Replaying database load with Percona Playback
If you are planning to upgrade or make any configuration change on your MySQL database the first advice usually is: – Benchmark! How should we do that benchmark? People usually run generic benchmark tools like sysbench, tpcc or mysqlslap that are good to know the number of transactions per seconds that a database can do [...]
Announcing Percona XtraDB Cluster 5.5.27-23.6
Percona is glad to announce the release of Percona XtraDB Cluster on September 7th, 2012. Binaries are available from downloads area or from our software repositories. Features: Percona XtraDB Cluster supports tunable buffer size for fast index creation in InnoDB. This value was calculated based on the merge block size (which was hardcoded to 1 [...]
MySQL Indexing Best Practices: Webinar Questions Followup
I had a lot of questions on my MySQL Indexing: Best Practices Webinar (both recording and slides are available now) We had lots of questions. I did not have time to answer some and others are better answered in writing anyway. Q: One developer on our team wants to replace longish (25-30) indexed varchars with [...]

