…is run in combination with heartbeat or pacemaker or something similar, and if one of the servers … can actually result in performance that’s worse than a single NIC.] The other two NIC …queries in the output of SHOW PROCESSLIST that might be a sign that trouble is brewing. Or if you watch your MySQL…
Post: More on MySQL transaction descriptors optimization
April 26, 2013 By Leave a Comment
… benchmarks on various combinations of hardware and dataset …two cases covered in the first post: single SELECT queries doing PRIMARY KEY lookups (aka QPS sysbench mode); same MySQL queries…combinations with taskset. The following chart shows a results comparison on a single-node (on the left) vs. two…
Post: Virident vCache vs. FlashCache: Part 2
May 17, 2013 By 3 Comments
… two-part series comparing Virident’s…of the evaluation points and combine that with the fact that the best vCache performance results…–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: Flexviews - part 3 - improving query performance using materialized views
April 4, 2011 By 20 Comments
… storing the results of a query in Memcache….two major factors: The cost (in terms of execution time) of the query…of the view, making it available for querying: mysql> call flexviews.enable( -> flexviews.get_id(‘demo’,'dashboard_customer_sales’)); Query…This is a combination of the ‘COMPUTE’ and ‘…
Post: Shard-Query turbo charges Infobright community edition (ICE)
May 6, 2011 By 23 Comments
…MySQL storage engines. This set of benchmarks evaluates how well Infobright community edition (ICE) performs in combination with Shard-Query…queries. This same SQL script was used in the Shard-Query tests. For the baseline, the results…
Post: How to find MySQL queries worth optimizing ?
September 11, 2012 By 6 Comments
…10Mil rows to produce result. What would be good scenario ? – query examining same amount of rows as they … is “const” MySQL does not count it as access to two tables. In case of “real” access …combined index. So what is the easy way to see if query is worth optimizing ? – see how many rows query…
Post: Multi Range Read (MRR) in MySQL 5.6 and MariaDB 5.5
March 21, 2012 By 10 Comments
…is the combined size of the secondary key tuples fetched, and N is the buffer size. In MySQL 5.6 … in numbers. Benchmark results For the purpose of this benchmark, I have used TPC-H Query #10 and ran …. However, when MRR is used then there are two separate calls made to the storage engine to …
Post: A workaround for the performance problems of TEMPTABLE views
May 19, 2010 By 7 Comments
… combination of integer values. There are enough values in the table such that a scan of all rows takes a second or two. mysql…result: mysql> select * from v2 where c1 = 10; +——+———-+ | c1 | count(*) | +——+———-+ | 10 | 130 | +——+———-+ 1 row in set (1.66 sec) Even a query…
Post: How to Monitor MySQL with Percona's Nagios Plugins
February 22, 2012 By 11 Comments
… cases also don’t log the resulting errors. The best place to …two instances of MySQL on the same files in the data directory, and refusing to shut down MySQL…to be monitored in two dimensions, which shouldn’t be combined: delay (Seconds_… and responds to a query. The pmp-check-mysql-status is also …
Post: Using index for ORDER BY vs restricting number of rows.
February 16, 2007 By 8 Comments
… to add all combinations of restrictions and order by to be fully indexed. An extra problem comes from the fact MySQL prefers when… in second query explain will look scary with estimated million of rows to analyze but we got rid of filesort so MySQL can stop… result. The speed difference between these two example queries is about 100 times so it may be quite serious. To fix this issue MySQL…
