… immediately a question arises how much logging impacts on performance. When we do performance audit often we log every query to find not only…. Each case had three options: logging turned off; logging queries which take more than a second to execute; logging every query; MySQL was run with…
Post: SSD, XFS, LVM, fsync, write cache, barrier and lost transactions
March 2, 2009 By 32 Comments
…enabled write-cache (which is default and most performance mode) does not warranty storing all InnoDB transactions…per_table=1 innodb_log_buffer_size=8M innodb_log_files_in_group=2 innodb_log_file_size=…last N commited transactions. So now time to turn off write-cache on SSD – all transactions are in…
Comment: Slow Query Log analyzes tools
June 10, 2008 By 83 Comments
… usage. I used a trick to turn off the general query log without restarting mysql – i moved the log file aside, touched a replacement… open a handle to the new general query log file, it simply stopped logging. Now, get an identical piece of hardware as… a fair performance test). Get the database on it current up to the point you turned on the general query log. To do…
Post: Paul McCullagh answers your questions about PBXT
November 20, 2009 By 2 Comments
…log-based architecture makes performance characteristics different to both MyISAM and InnoDB/XtraDB. Tests show that PBXT’s performance…What were the hard decisions or trade-offs that you had to make when designing… that do not exist. This, in turn, means that PBXT transactions are not SERIALIZABLE…
Post: MySQL Binaries Percona build10
December 11, 2008 By 12 Comments
…We addressed concerns about potential logging and statistics overhead, so now you can fully turn on / off query statistics for microslow patch… userstat_running | OFF | to control gathering of user statistics. With both slow_query_log = OFF and userstat_running = OFF we have no performance penalties …
Post: Setting up XFS on Hardware RAID -- the simple edition
December 16, 2011 By 9 Comments
…. Are there ways to squeeze more performance out of a server by dividing the…, utilized disks in the RAID. This turns out to be the same as …version 2 bsize=4096 ascii-ci=0 log =internal log bsize=4096 blocks=50608, version=2 ….el5 ro root=LABEL=/ noapic acpi=off rhgb quiet notsc elevator=noop This …
Post: The story of one MySQL Upgrade
October 8, 2010 By 8 Comments
…in the meanwhile we go over binary logs for the last month to see …these queries showed some results differences which turned out to be false positives too – …1 back to MySQL 5.0 and performed the same checks again – happily replication …and all it slaves as a slave off new master and keep it for some…
Post: Data mart or data warehouse?
July 15, 2010 By 13 Comments
…might be an ERP application, the logs from a web application, data …this complexity is an acceptable trade off for historical accuracy. This is often…? From a OLAP performance standpoint, many databases will perform better on a …the multi-dimensional query language. Mondrian turns MDX into SQL, so we’…
