…this configuration B. The next one contained four SSD-… for FlashCache. We can take a look at some…all run for 2 hours anyway, but I think…percentile=95 \ –mysql-user=root –mysql-socket=/tmp/mysql.sock –mysql-table-engine=innodb …cache_size = 1000 query_cache_size = 0 query_cache_type = 0 ft…
Post: Reasons for MySQL Replication Lag
July 29, 2011 By 9 Comments
…second which is 1.6MB/sec which may take 24+hours to feel 200GB buffer pool. Automatic …system which queries mysql. I’ve seen monitoring updates which would add excessively expensive and frequent query on … do not be mistaken, it is not always just one issue which is responsible for everything. Quite …
Post: Distro Packages, Pre-built Binaries or Compile Your Own MySQL
September 4, 2012 By 7 Comments
…one being they have been rigorously tested with the other components of your operating system. Take for example Ubuntu, the MySQL… alter MySQL‘s default behavior i.e. disabling and totally disallowing use of query cache … with MySQL? A paradigm shift like this can save your team tons of hours spent…
Post: Identifying the load with the help of pt-query-digest and Percona Server
December 29, 2011 By 3 Comments
…. However, there is one such tool, pt-query-digest (from Percona…_daily_summary wp_pp_hourly_summary wp_pp_hits wp_… query that is taking up the longest sum of run time, query …queries that you can use to gather more data about the underlying tables involved and the query execution plan used by MySQL…
Post: Faster MySQL failover with SELECT mirroring
February 1, 2009 By 9 Comments
One of my favorite MySQL configurations for high availability is master-master replication…use the standby (passive) master for serving some SELECT queries, taking backups, etc as usual. However, if you do … up a system so it’s actually responsive can take hours. As a result, the passive master isn’t …
Post: TPC-H Run on MySQL 5.1 and 6.0
April 10, 2008 By 16 Comments
… was 1 hour so query taking over 1 hour has NA. Times are given in seconds. Ratio is MySQL 6.0 time divided by MySQL 5… is only one query which does not complete within an hour in 5.1 and MySQL 6.0 can complete all queries within an hour. We… cut-off time to 3 hours to give MySQL more time to complete the queries: Query MySQL 5.0.23 MySQL 6.0.4Ratio Query13784.453737…
Post: Working with large data sets in MySQL
July 5, 2007 By 12 Comments
… with large data sets in mySQL teach you ? Of course you have to learn a lot about query optimization, art of building… after power failure as check and repair may take long hours (this is indeed one of the big reasons to use Innodb even… database size. Say it takes 30 minutes to alter 10GB table so it will take 5 hours to alter 100GB one. It can be…
Post: The MySQL optimizer, the OS cache, and sequential versus random I/O
April 28, 2008 By 17 Comments
… warehousing scenario. In short, a query that could take several days to run with one join order takes an hour with another, and the optimizer… not choose the faster one? That’s what this post is about. Let’s start with the MySQL query optimizer. The optimizer tries… MySQL query optimizer is a single random 4k data page read. In general, it’s a pretty good metric, but it has one…
Post: How to estimate query completion time in MySQL
April 22, 2008 By 16 Comments
Have you ever run a query in MySQL and wondered how long it’ll take to complete? Many people have had this experience…’ll take for the query to complete, depending on what the query is. One of the simplest is to estimate how many rows the query… an hour. And indeed the query completed in about 55 minutes. This is the simplest case, and there are more complicated ones to…
Post: Statement based replication with Stored Functions, Triggers and Events
December 16, 2011 By 4 Comments
… is the behavior of the MySQL when it needs to log “not usual” queries like Events, Functions, Stored …3) This behavior can be a problem to take in account or in some other cases help… CURRENT_TIMESTAMP + INTERVAL 1 HOUR DO INSERT INTO t VALUES(YEAR(CURDATE())) After one hour the event gets executed….
