…to IO resources which may not be available, especially for CPU bound MySQL…clearly much less than even single SATA hard drive can read sequentially. This file when will take about 10 seconds to…reading (from file cache) and piping to the /dev/null…looks like people are wondering how BZIP2 compares so I…
Post: Updated msl (microslow) patch, installation walk-through!
April 20, 2008 By 17 Comments
… determine how your current MySQL installation was built, so you can have the new binary to be as close to… file sql/slave.cc patching file sql/sql_cache.cc patching file sql/sql_class.cc patching…would be a proper flags set. To clear the filter just assign an empty string “” to this option. Note: you…
Post: Faster MySQL failover with SELECT mirroring
February 1, 2009 By 9 Comments
… the passive server’s caches start to get skewed to handle the write… for a long time. To measure how much this really matters, …0.48 The difference is clear. The buffer pool contains …to mirror the read-only workload to the passive server. It doesn’t have to be the tools I used — it could be MySQL…
Post: To UUID or not to UUID ?
March 13, 2007 By 28 Comments
…so it results are not absolutely clear but we already can have certain… to make load parallel but still small enough to be well cached. It is also worth to…be fixed in MySQL 5.1 Data Clustering This again applies to Innodb …be stored in optimized sort order to minimize how random they are – there …
Post: A case for MariaDB's Hash Joins
May 31, 2012 By Leave a Comment
…=’join_cache_incremental=on’ optimizer_switch=’join_cache_hashed=on’ optimizer_switch=’join_cache_bka=on’ join_cache_… to complete the above query: Here we can clearly see that MySQL 5.5 beats both BKA of MySQL… of the PK in the second table. How does optimizer work with the different Join Algorithms…
Post: Living with backups
November 6, 2008 By 28 Comments
… performance gains are quite clear. Now going back to flushing the data out of the cache. It happens …copy operation from MySQL data directory will result in a total disaster after MySQL stops responding to the …also a utility called ionice. It allows to affect how I/O scheduler will be dealing with …
Comment: When should you store serialized objects in the database?
January 21, 2010 By 47 Comments
… is that there is a clear loss in functionality. You…to their scalability. Treating MySQL like a key value store makes it dead simple to cache your objects. My Friendly library that you linked to…to conform to the performance characteristics of the database. It stinks of a lack of understanding of how…
Post: On Good Instrumentation
May 31, 2010 By 1 Comment
…as the time it took to generate HTML page we want to understand how much time was spent … see 2 queries taking 30 seconds it is clearly slow queries. If it is 10.000 queries…cache). This is important example as it shows your increased response time from MySQL may not have anything to do with MySQL…
Post: Just do the math!
July 6, 2009 By 4 Comments
…to solve. Let me start with example to make it clear. Lets say you’re doing some reports from your apache log files – how…no ability to predict it without running benchmarks. There are couple of ways MySQL may …fragmentation, on other hand there is also caching which may be taking place. Depends …
Comment: MySQL 5.6 vs MySQL 5.5 and the Star Schema Benchmark
March 12, 2013 By 7 Comments
…(the FS cache is the fastest IO possible). It seems to me (just my humble opinion) that MySQL should be usable…or bad settings, just different. Actually it isn’t clear if I can, because I haven’t tested the…and taking the time to post about it. I want to test other settings and see how they work, but …
