… me. Arrays in Prepared Statements Dealing with certain types of queries, ie queries with IN is so painful with prepared statements – I… very helpful in many cases. Multiple concurrent queries I would like to be able to run multiple queries for multiple MySQL connections at once. For scale…
Post: Flexviews - part 3 - improving query performance using materialized views
April 4, 2011 By 20 Comments
… are created by FlexCDC. The refresh algorithm computes changes in multiple transactions. After each transaction it must wait for FlexCDC to… view, making it available for querying: mysql> call flexviews.enable( -> flexviews.get_id(‘demo’,'dashboard_customer_sales’)); Query OK, 0 rows affected (41…
Post: Distributed Set Processing with Shard-Query
May 14, 2011 By 27 Comments
… the results back together again. This set logic allows to multiple levels of reduction of the set, all in parallel. All…% of the work, due to the multiple levels of result set reduction. Finally, Shard-Query can automatically partition sets into subsets using… of compute resource which speaks SQL, but right now only MySQL storage nodes are supported. Amdahl’s law applies to the…
Post: Using flow control functions for performance monitoring queries
May 24, 2008 By 12 Comments
… like IF or CASE used in MySQL Queries as they are often abused used to create queries which are poorly readable as well… MySQL Optimizer. One way I find IF statement very useful is computing multiple aggregates over different set of rows in the single query… request time as well as classifies requests to multiple classes. From the same query we can see portion of requests which were…
Post: The Doom of Multiple Storage Engines
May 8, 2010 By 22 Comments
One of the big “Selling Points” of MySQL is support for Multiple Storage engines, and from the glance view it is indeed… really this is not enough as MySQL allows you using multiple storage engines in the query you need to test all kinds of… enough. In fact people already do not love to mix multiple storage engines very actively because of potential complications involved. Now…
Post: MySQL Limitations Part 4: One thread per connection
October 27, 2010 By 14 Comments
… about the way MySQL handles connections, allocating one thread per connection to the server. MySQL is a single process with multiple threads. Not all databases are architected this way; some have multiple processes that communicate…, because of things like the lower startup cost for the query). But MySQL isn’t a data warehouse DBMS first and foremost…
Post: Data mart or data warehouse?
July 15, 2010 By 14 Comments
… Comparing the performance of OLAP with and without aggregation over multiple MySQL storage engines at various data scales. What is a data…database software supports hash joins, bitmap indexes, table partitioning, parallel query execution, clustered tables and materialized views. These features make …
Post: Shard-Query EC2 images available
May 11, 2011 By 2 Comments
… to distribute splitting and/or loading among multiple nodes as well. Note that in … from 1988 to 2010′; mysql> use ontime1; Database changed mysql> show table status like ‘ontime_…output from the ./run_query command, called pivot_results cd shard-query/ $ ./run_query < queries.sql | tee raw |./pivot…
Post: MySQL MyISAM Active Active Clustering - looking for trouble ?
March 15, 2007 By 4 Comments
… can use MySQL with Active Active Clustering and MyISAM tables if you follow certain rules like enabling external locking, disabling query cache… sense configure multiple MySQL servers this way. High availability ? This is where the biggest gotcha is waiting for you. If other MySQL node… really being compatible with such setup. As Oli describes even query cache which was implemented many years ago in 4.0…
Post: How Much memory do you use to run MySQL
November 2, 2012 By 8 Comments
… with MySQL Server related to amount of memory you have in the system – these range from problems with large size Query Cache… use to run MySQL Server these days ? [poll id="2"] Feel free to select multiple sizes if you have multiple kinds of instances… will be frozen so we do not get results from multiple years mixed.
