… that Shard-Query does not have to have any idea of the structure … of the work, due to the multiple levels of result set reduction. Finally…speaks SQL, but right now only MySQL storage nodes are supported. Amdahl’… dim_date.Year IN (2009) GROUP BY 1 ORDER BY NULL ) — AGGREGATION SQL: SELECT `origin_…
Post: Top 5 Wishes for MySQL
June 29, 2007 By 10 Comments
… tool set to deal with multiple nodes nicely even if you do not have much support from MySQL to do so. What is really bad is Parallel query. Reporting with group by over 10… years in MySQL I have created more than hundred of such little projects suggested by MySQL customers and myself based on long MySQL usage for…
Post: Join Optimizations in MySQL 5.6 and MariaDB 5.5
April 4, 2012 By 4 Comments
… could be reading the same page multiple times. Consider if you have a small buffer pool and a…_shipdate > ’1995-03-09′ group by l_orderkey, o_orderdate, o_shippriority order by revenue desc, o_orderdate LIMIT …at the status counters. Counter Name MySQL 5.5 MySQL 5.6 MySQL 5.6 w/ join_buffer_size=6M…
Post: Shard-Query turbo charges Infobright community edition (ICE)
May 6, 2011 By 23 Comments
…queries against a MySQL database by distributing the work over multiple machines and/or multiple cores. This … improve the performance of queries which have to examine a large amount of data… GROUP BY dest.CityName ORDER BY 2 DESC; Finally, Shard-Query performance continues to improve when grouping…
Comment: Database problems in MySQL/PHP Applications
August 11, 2006 By 13 Comments
… using multiple databases to group tables by certain logic, such as > you do with directories to group … frequently told by people with traditional database background. > Things are different with MySQL. Good design… the benefit versus the value added by having the benefit available. Making a blanket …
Post: Database problems in MySQL/PHP Applications
August 11, 2006 By 13 Comments
… often see applications using multiple databases to group tables by certain logic, such as you do with directories to group files. I think this… are needed – for example if grouping is done by user. This might be a bit extreem if you have thousands of users – I… MySQL. There are many successful applications, using tens of thousands of tables per host and archiving great performance by doing so. Using multiple…
Post: What would make MySQL Multiple Queries Usable ?
September 5, 2007 By 1 Comment
… and not significant gains in most cases. What would make MySQL Multiple Queries API more usable ? Allow to run queries in parallel… group by date to show history of matches per day. This could be very well optimized by performing search query only once while having multiple…
Post: A case for MariaDB's Hash Joins
May 31, 2012 By Leave a Comment
…than the join_buffer_size, then multiple hash tables would be created. … is that I have scaled down the time taken by MySQL 5.5 to finish…> ’1996-05-01′ GROUP BY o_orderkey ORDER BY num_items DESC LIMIT 10; …
Post: Quickly finding unused indexes (and estimating their size)
December 5, 2012 By 2 Comments
…risk dropping necessary indexes. To accomplish merging multiple result sets, I gathered statistics from …group by t.table_schema, t.table_name, i.index_name; Now I can query this view to see my indexes: mysql…question, but fortunately in Percona Server, we have it in the INFORMATION_SCHEMA.INNODB_…
Post: Jeremy Cole on MySQL Replication
May 27, 2006 By 12 Comments
… MySQL 5.0 – if you enabled Binary log with MySQL 5.0 you loose group commit which can dramatically increase commit rate for multiple user load. See this post by Vadim… problems. You still will practically have only One CPU to handle replication load. Furthermore if you have multiple disks they will not be…
