… in case of particular queries but surely cannot be an all-around answer to inefficiencies of the optimizer, that should be doing…
Post: Load management Techniques for MySQL
May 6, 2012 By 3 Comments
… problem, might be even not problem with your MySQL configuration, queries and hardware, even though fixing these does help in many… too much in this case throttling by having relatively short queries and introducing “sleeps” between them can be a good idea…
Comment: Learning about MySQL Table Fragmentation
May 18, 2012 By 19 Comments
… have set files_per_table variable. i executed the following query to know the fragmentation SELECT TABLE_SCHEMA, TABLE_NAME, CONCAT…
Comment: Benchmarking single-row insert performance on Amazon EC2
May 16, 2012 By 11 Comments
…, I am not testing IO performance and instead trying to optimize writes, also the durability requirements are not that stringent and…
Comment: Benchmarking single-row insert performance on Amazon EC2
May 16, 2012 By 11 Comments
… only a few GB of main memory). The cost of querying this database will be 10 times higher with this partitioning… 100 disk seeks to answer a random query, assuming you can get each index query down to one disk seek.) I claim…/head%3A/bench/ibench/iibench.py) is that it measures query performance too, so if you fail to actually index the…
Post: Benchmarking single-row insert performance on Amazon EC2
May 16, 2012 By 11 Comments
…_threads = 4 innodb_file_per_table = 1 ## Disabling query cache query_cache_size = 0 query_cache_type = 0 You can see that the…. Other then that, I have also disabled query cache to avoid contention caused by query cache on write heavy workload. OK, so… to reduce chances of log flush storms and disabling the query cache.
Comment: Joining many tables in MySQL - optimizer_search_depth
May 12, 2012 By 6 Comments
Bartosz, You are right this is due to an optimizer inefficiency. But till the time the optimizer is not efficient enough we would have to use workarounds. In fact hints tend to be used a lot because although mostly optimizer makes good choices but sometimes it doesn’t.
Comment: Multi Column indexes vs Index Merge
May 10, 2012 By 30 Comments
… are two explains that I executed for the same SQL query with a couple of mins gap on the same mysql prod instance . The first SQL query executed in 0.03 secs whereas the second SQL query when using index merge executes in…
Comment: How to convert MySQL's SHOW PROFILES into a real profile
May 10, 2012 By 10 Comments
Thanks for the post. A newbie comment here, I noticed that the inclusion of a function (user defined) in a query excludes it from PROFILES. Any workaround?
Post: Introducing Zend DBi as a MySQL Replacement on IBM i
May 8, 2012 By Leave a Comment
…, management scripts, or anything else. There is no difference in query syntax, client-server protocol, or data storage on disk. Anything…
