… have been working for a customer benchmarking insert performance on Amazon EC2, and…so that we can see the impact of growth in data-set on the insert rate. We can see that adding …can be classified as large, because it varies between ~6.5k to ~12.5k INSERTs per second, with noticeable spikes after …
Post: Troubleshooting MySQL Memory Usage
March 21, 2012 By 3 Comments
…. Is it working with large blobs ? Using user variables ? …data_length+index_length) from information_schema.tables where engine=’memory’; +——————————-+ | sum(data_length+index_length) | +——————————-+ | 126984 | +——————————-+ 1 row in set…
Post: How FLUSH TABLES WITH READ LOCK works with Innodb Tables
March 23, 2012 By 20 Comments
…WITH READ LOCK can be quite large…WITH READ LOCK does not work as optimally as you could think it works. Even though with… 5 rows in set…with Percona Xtrabackup. Many other tools have similar option. This option can be especially helpful when backing up data from the slave with…
Post: Join Optimizations in MySQL 5.6 and MariaDB 5.5
April 4, 2012 By 2 Comments
… This join algorithm only works with equi-joins. Now let me briefly explain how hash join algorithm works. Suppose you … 5.5 While with join_buffer_size set to 6M and read_rnd_buffer_size set to 6M, the …data is read from disk 2.2G vs 5G. However, there is one number in MariaDB 5.5 that is quite large…
Post: Multi Range Read (MRR) in MySQL 5.6 and MariaDB 5.5
March 21, 2012 By 10 Comments
….89G 1.53G 1.89G 1.53G Innodb_data_reads 120552 123872 100551 103011 77213 Innodb_pages_… key lookups as well. But this works only with joins and specifically with Block Access Join Algorithms. So I …query time is reduced further when buffer size is set large enough so that the index tuples fit in …
Post: Working with large data sets in MySQL
July 5, 2007 By 12 Comments
What does working with large data sets in mySQL teach you ? Of course you have to learn … learn when working with large data things in MySQL is patience and careful planning. Both of which relate two single property of large data sets – it can…
Post: Why MySQL could be slow with large tables ?
June 9, 2006 By 139 Comments
… requires you to be extra careful working with large data sets. In MySQL single query runs as single thread (with exeption of MySQL Cluster) and MySQL… aggregate result sets. So if you’re dealing with large data sets and complex queries here are few tips Try to fit data set you’re working with in…
Post: PHP Large result sets and summary tables.
July 6, 2007 By 8 Comments
We’re working with web site preparing for massive growth. To make sure it handles large data sets as part of the process we work on generation test database of significant size as testing your application on table with… run other queries, ie INSERTs and UPDATEs while you traverse with data. Not with unbuffered query because connection is still busy. Need more…
Page: Consulting for MySQL
July 31, 2006 By
… Want your developers to learn MySQL best practices ? How to work with large data sets in MySQL or how to optimize queries ? Customized training will…. Data Recovery for MySQL Lost your data due to corruption, hardware failure or developer error ? We’ll work with you to recover as much data…
Comment: Why MySQL could be slow with large tables ?
June 14, 2006 By 139 Comments
… missunderstood this article. I’m writing about working with large data sets, these are then your tables and your working set do not fit in memory. This… article my first advice is to try to get your data to fit in cache. If it is possible you instantly… of the problems solved. And yes if data is in memory index are prefered with lower cardinality than in case of disk…
