… the use of subqueries/multiple joins vs. multiple queries (e.g. temp tables)? For performance, it’s hard to make a general… query that took half the time. An important conclusion of my presentation today is that sometimes you find unexpected differences in performance like this, so it pays to test all different solutions, and measure the resulting performance! Q: Bill, back to the query where…
Post: Webinar: SQL Query Patterns, Optimized
May 20, 2013 By Leave a Comment
… training and consulting, I’ll classify several common types of queries with which developers struggle. I’ll test several SQL solutions… analyze them for optimal query efficiency. The discussion will cover optimizer reports, query profiling, and session status to measure performance. The query patterns will include…
Post: Benchmarking Percona Server TokuDB vs InnoDB
May 7, 2013 By 32 Comments
… Server with TokuDB, of course I wanted to compare InnoDB performance vs TokuDB. I have a particular workload I’m interested… and TokuDB performs if PK is (`id`,`hid`,`mid`). This also will affect select performance, so we will need to measure that also… join_buffer_size = 4M thread_cache_size = 1000 query_cache_size = 0 query_cache_type = 0 ft_min_word_len = 4 #default…
Post: Percona Playback 0.6 for MySQL now available
April 9, 2013 By 1 Comment
… read queries from MySQL query-log and MySQL tcpdump files and run them on other MySQL server. With Percona Playback you can measure how a server or database upgrade, change in my.cnf or schema change can affect the overall performance of… MySQL database server. Bug fixed #1070824 (Vlad Lesin). Multi-line query parsing has been improved. Bug fixed #1080648 (Vlad Lesin). Missing…
Comment: Benchmarking single-row insert performance on Amazon EC2
May 16, 2012 By 17 Comments
…’s a theory that seems to explain the performance you are seeing. The periodic performance variation corresponds to filling up a partition…’t graph the performance on the first 100M rows). The minimum performance troughs occur just as the partition switches. So performance gets worse…/annotate/head%3A/bench/ibench/iibench.py) is that it measures query performance too, so if you fail to actually index the data…
Post: Cache Performance Comparison
August 9, 2006 By 74 Comments
… anyway, I decided to check peak performance of all caches compared to MySQL Server, by measuring just the time it takes cache… ? Simply we perform 10.000 of get requests from cache, which was previously populated to contain value and measuring how long does… Query Cache (Unix Socket) 13500 Selecting from table (TCP/IP) 5100 Selecting from table (Unix Socket) 7400 Note: The test measures peak performance…
Post: The new cool MySQL patch has landed! Check your queries performance!
October 31, 2007 By 16 Comments
… time their queries and to catch those which run less than a second as they can also be a performance killer for… parameter –log-slow-slave-statements. THE DETAILED INFORMATION ABOUT QUERY EXECUTION Each query can be executed in various ways. For example it… be done asynchronously, unfortunatelly there is no good way to measure that. InnoDB_IO_r_bytes is the corresponding value in…
Post: Intro to OLAP
July 12, 2010 By 10 Comments
… tool must generate to answer those queries. Performance challenges with larger databases, and some ways to help performance using aggregation. Using materialized views… example, in a sales analysis, the “sale amount” is a measure. Measures are always aggregated values. That is, total sales might be…
Post: The two even more fundamental performance metrics
May 5, 2011 By 6 Comments
… that little spike. We could also classify queries together and analyze the classes of queries, rather than lumping all requests into one… to derive pretty much everything else about a system’s performance (via measuring response times), scalability (via the four fundamental metrics I…
Post: Read/Write Splitting with PHP Webinar Questions Followup
January 23, 2013 By 4 Comments
… don’t seem to measure slave lag. They seem to assume that all slaves are ready to be queried all the time… in the MySQL database for persistence, but when we measured query load with pt-query-digest, we found that 30% of the database… be a high performance cost? A: Connecting to a MySQL database isn’t a great performance cost, compared to the queries themselves. If…
