…’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: Introducing new type of benchmark
February 25, 2012 By 16 Comments
…, but started to use widely) a benchmark methodology when we measure not the final throughput, but rather periodic probes (i.e… added to a total response time. As a result we measure 95% or 99% response times. What does it give to… problem with DROP TABLE performance. Does DROP TABLE, running in separate session, affect a response time of queries that handle user load…
Post: Cache Performance Comparison
August 9, 2006 By 73 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 9 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: Impact of logging on MySQL’s performance
February 10, 2009 By 7 Comments
… logging impacts on performance. When we do performance audit often we log every query to find not only slow queries. A query may take less… 5 times and random measurement error was calculated. As it is seen from the chart above the performance almost doesn’t depend on logging – the difference doesn’t exceed the measurement error. The query rate in…
Post: Modeling MySQL Capacity by Measuring Resource Consumptions
March 8, 2011 By 1 Comment
… the system to predict in performance, the model baron has published for example is good for measuring scalability of the system as… at CPU and IO consumption per Query and compare it to estimated (or benchmarked) system performance to provide our estimates. If we… interesting to look at Per-query information from mk-query digest (I omit queries text for client privacy) # Query 1: 0 QPS, 0x concurrency…
Post: How to estimate query completion time in MySQL
April 22, 2008 By 14 Comments
… on what the query is. One of the simplest is to estimate how many rows the query needs to examine, measure how fast…’ll write more about that later) I convinced MySQL to perform the query as a table scan of the fact table, then… let you do that.) The solution was to measure how fast the query was scanning rows in the table scan of the…
Post: Goal driven performance optimization
December 22, 2008 By Leave a Comment
… about percentile response time rather than “all queries“. It is surely good all search queries complete in one seconds but it is….000 images uploaded and measure the response time for them specifically because this group has its own performance challenges. Looking at Latency… mention looking at performance statistics for the day overall is often not enough. Application performs as good as it performs during its worst…
