… me rephrase the use case — * The entire table is too big to be cached, but * One partition is small enough to… about Percona or MariaDB. (Re #4) There are _no_ parallel queries (within a single connection) anywhere in any ‘free’ variant of… if you find otherwise.) I would argue that single-row queries (SELECT, INSERT, DELETE, UPDATE) are similar in speed between PARTITIONed…
Comment: Why MySQL Performance at Low Concurrency is Important
March 31, 2013 By 8 Comments
… to 200 usecs) queries: * performance_schema overhead is too high for benchmarks * innodb_checksum_algorithm=CRC32 is a big win * 5.6…
Post: Why MySQL Performance at Low Concurrency is Important
March 27, 2013 By 8 Comments
… times (MySQL server does not use multiple threads to execute query in parallel at this point). Response times at the variety… Santa Clara, California, where “performance” is going to be a big topic 
Post: Shard-Query EC2 images available
May 11, 2011 By 2 Comments
… makes a big difference In general, a column store performs about 8x-10x better than a row store for queries which access a significant amount of data. One big reason for this is the excellent… will summarize the output from the ./run_query command, called pivot_results cd shard-query/ $ ./run_query < queries.sql | tee raw |./pivot_results & [1…
Post: Air traffic queries in InfiniDB: early alpha
November 2, 2009 By 19 Comments
… +——-+——+————————————————————+ Ok, so InfiniDB does not support DERIVED TABLES, which is big limitation from my point of view. As workaround …able to start. After that query Q4 took 0.75 sec Queries Q5-Q7 skipped. Query Q8: SELECT DestCityName, COUNT( …
Post: MySQL 6.0 vs 5.1 in TPC-H queries
March 25, 2008 By 17 Comments
…, which should affect execution plan of TPC-H queries. In reality only two queries (from 22) have significantly better execution time (about… I want to write about is queries that execute slower in new MySQL 6.0 version. Query is pretty simple SELECT sum… so big we could speak about big improvements with using MRR here. What is interesting is iostat -dx 5 output during query execution…
Post: Shard-Query adds parallelism to queries
November 15, 2010 By 18 Comments
…) when running small numbers of queries which examine a lot of data. What is Shard-Query? Shard-Query was initially conceived as a… that Shard-Query performs better is that it turns the OLAP query into something more like OLTP. Instead of getting one big chunk of data in one query, it runs many smaller queries each…
Post: How to Identify Bad Queries in MySQL
January 10, 2011 By 16 Comments
Finding bad queries is a big part of optimization. A scientific optimization process can be simplified … queries that block other queries — yet. The missing piece, part 3 — finding queries that block other queries — is best done by observing clusters in query…
Post: Handling big result sets
June 26, 2006 By 13 Comments
… database’); $time_start = microtime(true); // Performing SQL query $query = ‘SELECT * FROM longf’; $result = mysql_query($query) or die(‘Query failed: ‘ . mysql_error()); // retrive result while…_unbuffered_query() sends a SQL query query to MySQL, without fetching and buffering the result rows automatically, as mysql_query() does. So mysql_query buffers…
Post: How to estimate query completion time in MySQL
April 22, 2008 By 16 Comments
… people have had this experience. It’s not a big deal until the query has been running for an hour. Or a… how long it’ll take for the query to complete, depending on what the query is. One of the simplest is to… that SHOW GLOBAL STATUS showed what that one query was doing; activity from other queries would have been mixed in there too…
