…to under a minute. The query time is reduced further when the buffer size is set to 4M. Note also that query…improvement and changes needed in the optimizer’s cost estimation algorithm. MariaDB 5.5 expands the concept of MRR to improve the performance…
Post: Join Optimizations in MySQL 5.6 and MariaDB 5.5
April 4, 2012 By 2 Comments
… extended to improve join performance. As I told you above, when table t1 would be joined to table t2…; In-memory workload Now let’s see how effective are the join optimizations when the …to know is that, just increasing the join_buffer_size is not going to provide the best possible query performance…
Post: Index Condition Pushdown in MySQL 5.6 and MariaDB 5.5 and its performance impact
March 12, 2012 By 12 Comments
I have been working with Peter in preparation for the talk comparing the optimizer enhancements in MySQL 5.6 and MariaDB 5.5. We are taking a look at and benchmarking optimizer enhancements one by one. So in the same way this blog post is aimed at a new optimizer enhancement Index Condition …
Post: Introducing new type of benchmark
February 25, 2012 By 16 Comments
…), how does it affect the response time ? – When we put a load to two nodes instead of three nodes, will it help to improve the response time ? – Do we need to increase number… performance. Does DROP TABLE, running in separate session, affect a response time of queries that handle user load ? The same for mysqldump, how…
Post: Joining many tables in MySQL - optimizer_search_depth
April 20, 2012 By 5 Comments
… full query execution time to less than 50ms. Low values, such as 3,4 provided a bit better performance but … joins with few tables, – it is not clear how far from optimal plans do we get by … are likely to get even better handling joins of many tables as optimizer heuristics are improved so much …
Post: Flexviews - part 3 - improving query performance using materialized views
April 4, 2011 By 12 Comments
… the original query execution time. It may be possible, therefore, to refresh an MV based on a query that takes 45 minutes to execute…(), it but still provides improved performance during refresh by accessing summarized data. I hope this helps you understand how Flexviews can help you…
Post: Shard-Query turbo charges Infobright community edition (ICE)
May 6, 2011 By 22 Comments
… be exploited by scale up. Scale up can improve query performance when there is enough resources to support the added parallelism, and when one… 1 ORDER BY c LIMIT 10; The next queries show how performance is improved when Shard-Query adds parallelism when “subqueries in the from clause…
Post: How Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
… If you don’t know how to read these, there’s a full explanation in our book, High Performance MySQL 2nd Edition (it… glance whether a query is going to be possible to improve a lot, and a simple mental calculation can then tell me how much total gain I can get from it. Queries…
Post: How to Identify Bad Queries in MySQL
January 10, 2011 By 16 Comments
…to improve it? – if not, we’re done.” In databases, we care most about the work the database is doing. That is, queries…queries blocking others, but it’s nowhere near precise enough to find and diagnose the kinds of sub-second performance…
Post: High-Performance Click Analysis with MySQL
December 22, 2008 By 13 Comments
… the most common questions we hear is how to build high-performance systems to do this work. Let’s see…a lot about how you need to query the data. It is a hard question to answer, and … primary key(day, ad, is_blue) ); What can we improve here? Especially assuming that there are indexes other…
