… the serial version as run by the native database interface (MySQL): mysql> select word, md5(word), md5(reverse(word)), count(*) from words2… operation burns one CPU. To help completely demonstrate how Shard-Query makes parallel set operations work, I’ll operate in only one dimension for the first example, just like the MySQL client. This will be a linear…
Post: Using any general purpose computer as a special purpose SIMD computer
May 16, 2011 By 5 Comments
Post: MySQL Wish for 2013 - Better Memory Accounting
December 31, 2012 By 6 Comments
…as well as where CPU resources are spent. (Performance Schema does not accounts CPU usage directly but …to understand what memory is currently used for. One thing to note with memory allocation is …monitoring it which I’m sure hosting providers, MySQL as a Service vendors will especially appreciate as…
Post: Jeremy Cole on MySQL Replication
May 27, 2006 By 12 Comments
Jeremy Cole recently posted very nice post about MySQL Replication Performance. There are however few points I should comment … flush their cache. Watch out for MySQL 5.0 – if you enabled Binary log with MySQL 5.0 you loose group commit… not solve all problems. You still will practically have only One CPU to handle replication load. Furthermore if you have multiple disks…
Post: Top 5 Wishes for MySQL
June 29, 2007 By 10 Comments
… Be Distributed One of the most common buzzwords used together with MySQL is Scale Out, but to say the truth MySQL does not… still can’t deny – MySQL does not handle complex queries well, being able to use only one CPU effectively on single node and no true federation support. 4. Be Solid MySQL has very good stability…
Post: Auditing login attempts in MySQL
December 28, 2012 By 4 Comments
… our MySQL Support customers: How can I audit the login attempts in MySQL? Logging all the attempts or just the failed ones is a very important task on some scenarios. Unfortunately there are not too many audit capabilities in MySQL Community…: 25 CONCURRENT_CONNECTIONS: 0 CONNECTED_TIME: 464 BUSY_TIME: 96 CPU_TIME: 19 BYTES_RECEIVED: 62869617 BYTES_SENT: 14520 BINLOG_BYTES…
Post: How Percona diagnoses MySQL server stalls
March 3, 2011 By 6 Comments
…to gather snapshots of waiting (stack traces) and CPU consumption (oprofile). That’s important because sometimes the…commands you can use. If you find that one of the samples looks suspicious, you can … many things that can cause a stall in MySQL, and they usually begin microscopically and get worse…
Post: Learning about MySQL Table Fragmentation
May 1, 2008 By 20 Comments
… some small index instead. If your table is not fragmented one of two things should happen – either you should be reading… your hard drive sequential read rate or you would see MySQL becoming CPU bound if IO subsystem is too fast. In this…
Post: How Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
… 25 /proc/cpuinfo power management: processor : 7 vendor_id : GenuineIntel cpu family : 6 model : 15 model name : Intel(R) Xeon(R…=/var/db/mysql –user=mysql –pid-file=/var/run/mysqld/mysqld.pid –skip-external-locking –port=3306 –socket=/var/db/mysql/mysql.sock consult… output. The stock MySQL server’s limitation of one-second granularity makes it hide problem queries that are faster than one second (which…
Post: MySQL 5.6 vs MySQL 5.5 and the Star Schema Benchmark
March 11, 2013 By 7 Comments
…. One particular point of investigation which needs to be followed up on, including testing innodb_old_blocks_time=1000 on MySQL 5… only one join, I’ve tested performance of the query with the join in both directions. Explain for query Q1.1: mysql… state, p1.duration, p2.duration, p1.cpu_user + p1.cpu_system p1_cpu, p2.cpu_user + p2.cpu_system p2_cpu, p1.context_voluntary + p1.context…
Post: MySQL caching methods and tips
April 4, 2011 By 5 Comments
… for MySQL. Popular cache methods The MySQL query cache When the query cache is enabled, MySQL examines …the sorting, aggregation and join operations are still CPU intensive and single threaded. In order to …Conclusion If the least expensive queries are the ones you never run, then the most expensive …
