… seeks to answer a random query, assuming you can get each index query down to one disk seek.) …, you didn’t graph the performance on the first 100M rows). The minimum performance troughs occur just … partition starts getting too big, so Inno starts slowing down again. The factor of 4 speedup that …
Post: Join Optimizations in MySQL 5.6 and MariaDB 5.5
April 4, 2012 By 2 Comments
…. This join algorithm works best for highly selective queries, and obviously when the first operand used in the build step is such… is quite slow as compared to both MySQL 5.5 and MySQL 5.6. For MariaDB 5.5 the query time decreases…_init’. Is it because of this that the query on MariaDB 5.5 is slow as compared to MySQL 5.6. Next…
Post: Troubleshooting MySQL Memory Usage
March 21, 2012 By 3 Comments
…some troubleshooting techniques I use. Plot Memory Usage First I would like to see MySQL memory consumption … are implicit MEMORY tables which are allocated for query execution, which size can be controlled by tmp…to detect memory leaks like valgrind are too slow to run in production. So the best …
Post: MariaDB 5.3 is released as GA!
March 5, 2012 By 17 Comments
… last week, so we are a little slow to blog about this and acknowledge the …remember that our support contracts cover MariaDB as a first-class member of the MySQL family of databases….much faster with the binary log enabled Faster queries through speedier joins, faster subqueries, and elimination …
Post: MySQL Slow query log in the table
May 31, 2007 By Leave a Comment
As of MySQL 5.1 get MySQL slow query log logged in mysql.slow_log table instead of the file as you had… confused me first is the order query come in the log file. If you used to do tail -100 log-slow.log and… to aggregate log entirely in SQL finding most frequent slow query types or queries which load server the most. The other handly feature…
Comment: Multi Column indexes vs Index Merge
March 12, 2010 By 30 Comments
…), lastname(2)); The requirement is for wildcard searching on the first character on the firstname and lastname. select firstname, lastname from… query it takes more than a minute to finished the query. All subsequent query is a snap. So the problem is on the first query… am getting “504 Gateway Time-out” error because of this slow first query. Any thoughts about myqsl warm up? and how to improve…
Post: Slow Query Log analyzes tools
September 6, 2006 By 83 Comments
… really slow queries but to really optimize application throughput queries which generate most of the load need to be investigated Patching Slow Query Logging – First thing… same slow query log first to fix worse queries and then come to find more optimization candidates. So “tail -f mysql-slow.log | mysql_slow_log…
Post: Identifying the load with the help of pt-query-digest and Percona Server
December 29, 2011 By 3 Comments
… pt-query-digest Using pt-query-digest is pretty straight forward: pt-query-digest /path/to/slow-query.log Note that executing pt-query-digest can… with analysis of the query that is taking up the longest sum of run time, query ranked #1. The first row in the table above shows the Count of number of times this query was executed…
Post: Why MySQL could be slow with large tables ?
June 9, 2006 By 139 Comments
…accesses/index scans. For example retrieving index values first and then accessing rows in sorted order … which is completely disk bound can be very slow. One of the reasons elevating this problem …IO requests one by one for query execution, which means if single query execution time is your concern…
Post: Optimizing slow web pages with mk-query-digest
April 7, 2011 By 14 Comments
… – I had a slow query log (captured with long_query_time=0 and all the eXtra benefits from Percona slow query log patch), I knew… mk-query-digest: mk-query-digest –filter=’$event->{Thread_id} == 160847′ in > out Now I know exactly what needs to be fixed first to make the greatest impact to this page response time. I can also convert that into a slow query log…
