… Percona Server 5.6.10 sandbox: description=MySQL driver=com.mysql.jdbc.Driver connectionSpec=jdbc:mysql://127.0.0.1:5610/schemaspy driverPath=/usr/share/java/mysql-connector-java.jar Example Schema… tool. There are additional tabs: Tables – Names, number of children, parents, count of columns, row counts, and comments — a great way for…
Post: MySQL Query Patterns, Optimized - Webinar questions followup
June 3, 2013 By 2 Comments
… a presentation on “MySQL Query Patterns, Optimized” for Percona MySQL Webinars. If you missed it,… 50000 with no movies, but your random number generator picks values in that range with…frequently. Nearly every solution for randomly choosing rows involves some compromise, either of performance, or…
Post: MySQL and the SSB - Part 2 - MyISAM vs InnoDB low concurrency
May 22, 2013 By Leave a Comment
… a “flight”. I have labeled each query as Q{FLIGHT_NUMBER}.{QUERY_NUMBER}. In general, each flight examines different time periods or… data. It seems that InnoDB performs better when a larger number of rows must be joined together (Q4.1, Q4.2) but… [mysqld] datadir=/mnt/mysql56/data basedir=/usr/local/mysql socket=/var/lib/mysql/mysql.sock user=justin innodb_buffer_pool_size=64G innodb…
Post: Choosing a MySQL HA Solution - Post-Webinar Q&A
June 7, 2013 By Leave a Comment
…occurs. For example, if you see a large number of long-running queries in the output of… in file: ‘./mysql/servers.frm’ ERROR: 1033 Incorrect information in file: ‘./mysql/servers.frm’ Running mysql_install_db under …with –skip-grant-tables and insert a few rows into an InnoDB table, but trying to …
Post: Understanding the maximum number of columns in a MySQL table
April 8, 2013 By 5 Comments
…: “What is the maximum number of columns in MySQL?” and “What is the minimum maximum number of columns in MySQL?”. Before you read on… play around the maximum number of columns is this: /* Hack to avoid bugs with small static rows in MySQL */ reclength=max(file->min… out the maximum number of columns in a MySQL table. So what’s the maximum number of columns in a MySQL table? Well.. I…
Post: Is Synchronous Replication right for your app?
May 14, 2013 By 18 Comments
…as they don’t touch the same row. Row locks are held for modifications until …standard MySQL replication from this instance, since MySQL replication is asynchronous. What about semi-sync MySQL replication… However, each autocommit is retried only the number of times specified by this variable (…
Post: More on MySQL transaction descriptors optimization
April 26, 2013 By Leave a Comment
… Dimitri Kravchuk, we have received a large number of questions on why the benchmark results… Dimitri was using 8 tables with 1M rows each (about 2.1GB) for his tests,…0 –percentile=99 –mysql-user=root –mysql-db=sbtest8t1M –mysql-table-engine=INNODB –mysql-socket=/tmp/mysql.sock –oltp-point-…
Post: Virident vCache vs. FlashCache: Part 2
May 17, 2013 By 3 Comments
… were conducted with approximately 78GiB of data (32 tables, 10M rows each) and a 4GiB buffer pool. The cache devices were… of the way, let’s look at some numbers. vCache vs. vCache – MySQL parameter testing The first test was designed to look… exact same pattern when looking at transaction latency; the baseline numbers are roughly identical for all four configurations, but configuration C…
Post: Modeling MySQL Capacity by Measuring Resource Consumptions
March 8, 2011 By 1 Comment
… restrictions, such as row level locks. There is also a load aspect – “random arrivals” tell us the number of work system has… ? You can take a look at procfs for MySQL process: root@ubuntu:/var/log/mysql# cat /proc/19018/stat 19018 (mysqld) S… IO (which you can see separately through number of IOPS) but it also can be row level locks, etc. The ratio between…
Post: Why MySQL could be slow with large tables ?
June 9, 2006 By 141 Comments
… probably heard complains about MySQL being unable to handle more than 1.000.000 (or select any other number) rows by some of the users. On other hand it is well known with customers like Google, Yahoo, LiveJournal,Technocarati MySQL… by index: mysql> select count(pad) from large; +————+ | count(pad) | +————+ | 31457280 | +————+ 1 row in set (4 min 58.63 sec) mysql> select count…
