… of places where memory could be allocated but it is a lot larger problems with MySQL 5.5 with addition of user… if you close connection. In Percona Server you can do better as you can query temporary tables too: mysql> select sum… common thing about memory leaks is because it is memory which is allocated and forgotten about, unless it is very small blocks, it should…
Post: Are larger buffers always better ?
June 6, 2006 By 9 Comments
… see people thinking about buffers as “larger is always better” so if “large” MySQL sample configuration is designed for 2GB and they happen to… of times but only few rows were sorted. 32K block is allocated fully in user space, while 32M block requires mmap…_cache may cause long stalls on invalidation. Configure it smart. Larger is not always better 
Post: Shard-Query adds parallelism to queries
November 15, 2010 By 16 Comments
… is could better utilize all available resources (that is, scale better) when running small numbers of queries which examine a lot of data. What is… real cores and 384GB of ram. The amount of ram is significantly larger than my already hefty 55GB testing data set, so….09081411361714.737620115286.07981824874886.0321369171143 The reason that Shard-Query performs better is that it turns the OLAP query into something more like…
Post: Heikki Tuuri Innodb answers - Part I
October 26, 2007 By 17 Comments
… the row is less than 8100 bytes InnoDB will not allocate additional space for blobs, even if each blob is larger than 768… happens for blobs larger than 16K – is exact size allocated or also segment based allocation is used. Q18: Innodb Q: Is Group commit still… to use only couple of CPUs efficiently. Thought even that is often better than bad thrashing. Q22: Also, What’s the deal…
Comment: Are larger buffers always better ?
June 6, 2006 By 9 Comments
[...] Are larger buffers always better ?: “Sometimes I see people thinking about buffers as ‘larger is always better‘ so if ‘large’ MySQL sample configuration is designed for 2GB and they happen to have 16, they would simply multiply all/most values by 10 and hope it will work well. [...]
Post: Aligning IO on a hard disk RAID – the Benchmarks
June 9, 2011 By 11 Comments
… however, the effect disappeared and performance without LVM was slightly better than with LVM as expected. I had to redo all… from the OS perspective is very similar, due to high concurrency response time in the first case is significantly better. It would be interesting however to run similar benchmarks on a larger RAID5 system where it…
Post: Computing 95 percentile in MySQL
November 28, 2008 By 5 Comments
… and average is not a good fit here. Defining your response time goal in 95 or 99 percentile is much better. Say you…/page views are allowed to take more than that. For larger systems defining (increasing) response times for 99.9 or even… for larger amount of delays. Be careful though – the “random” delays, for example if system was busy and delayed servicing request is…
Post: MySQL 5.0, 5.1 and Innodb Plugin CPU Efficiency
December 3, 2008 By 15 Comments
… efficient, on the contrary newer features often come together with larger code and longer execution path. Another thing to note – if… synchronization is the issue. Barracuda format uses more CPU while delivering better performance so it is probably better with latching too though it is hard…
Post: Data mart or data warehouse?
July 15, 2010 By 13 Comments
… tool must generate to answer those queries. Performance challenges with larger databases, and some ways to help performance using aggregation. Using… schemata.”][/caption] Is one better than the other? In the game of data warehousing, a combination of these methods is of course allowed… database increases. So what is the big deal? From a OLAP performance standpoint, many databases will perform better on a star schema…
Post: MySQL-Memcached or NOSQL Tokyo Tyrant - part 3
October 19, 2009 By 25 Comments
… So for this particular application I would have been much better off not storing my data in MySQL and instead looking… an application requires a database great, but if there is a better solution we want to suggest it. It’s our… ( why a smaller buffer pool? This simulates a much larger data set. A BP of 256M with 1GB of…
