…-queries-in-infinidb-early-alpha/). Addressing these issues, I took Star Schema Benchmark, which is TPC-H modification, and tried run queries… be resolved by InfoBright optimizer and I need to enable MySQL optimizer. InfiniDB is otherwise was IO-bound, and processed data… scalability on InfiniDB’s blog http://infinidb.org/infinidb-blog/mysql-parallel-query-processing-of-ssb-queries-via-infinidb-.html SSB…
Post: Data mart or data warehouse?
July 15, 2010 By 13 Comments
… OLAP analysis usually is performed on a star schema which partially denormalizes the data. A star schema about a particular subject matter, such as… are not as popular as star schemas because they tend to not perform as well as a star schema, particularly as the volume of… working with a star schema much easier than it may be on MySQL, but it is definitely possibly to use MySQL as long as…
Post: Performance Schema tables stats
May 2, 2011 By 2 Comments
… are able to get from performance schema tables. 1. table_io_waits_summary_by_table mysql> select * from table_io_waits_summary… mysql> select OBJECT_NAME,COUNT_STAR from table_io_waits_summary_by_table order by COUNT_STAR DESC LIMIT 5; +————-+————+ | OBJECT_NAME | COUNT_STAR…
Post: Shard-Query turbo charges Infobright community edition (ICE)
May 6, 2011 By 22 Comments
…desirable to benchmark using a star schema, even though it involves work to transform the data. Star schema Transforming the data was…sec) Each year has tens of millions of flights: mysql> select count(*) from ontime_one.ontime_fact; +———–+ | count(*) | +———–+ | 135125787 | …
Post: High-Performance Click Analysis with MySQL
December 22, 2008 By 13 Comments
… you should use traditional DW methods, like star schemas. The problem is that MySQL doesn’t tend to perform well on a… some of MySQL‘s weaknesses in some cases. Not only that, but star schemas are not intended to be fast. The star schema is essentially… a lot of rows — MySQL can’t handle too many of those at once. Aside from star schemas, another tactic I see people…
Post: How Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
… of the smallest levers we can pull for server optimization. Schema and query optimization can give much greater improvements, for example…=/var/db/mysql –user=mysql –pid-file=/var/run/mysqld/mysqld.pid –skip-external-locking –port=3306 –socket=/var/db/mysql/mysql.sock consult… these things operate. For example, if the workload is a star schema data warehouse, it is important to know a lot about…
Post: The MySQL optimizer, the OS cache, and sequential versus random I/O
April 28, 2008 By 17 Comments
… on a join between a few tables in a typical star schema data warehousing scenario. In short, a query that could take…Avg_row_length: 117 Data_length: 17217646764 Index_length: 11993816064 mysql> show table status like ‘dim1′\G *************************** 1. row *************************** Name: dim1…
Post: How to estimate query completion time in MySQL
April 22, 2008 By 14 Comments
Have you ever run a query in MySQL and wondered how long it’ll take to complete? Many … star schema query. The fact table was very large, and after some tuning (I’ll write more about that later) I convinced MySQL… to choose another thread and watch only its status, but MySQL doesn’t currently let you do that.) The solution was…
Post: Distributed set processing performance analysis with ICE 3.5.2pl1 at 20 nodes.
May 14, 2011 By Leave a Comment
… raw input data set was 55GB before converting to a star schema (21GB) and being compressed by ICE to 2.5GB. Many…
Post: Intro to OLAP
July 12, 2010 By 9 Comments
… intelligence tools, particularly OLAP (or online analytical processing) tools using MySQL and other free open source software. OLAP tools are a… structured as a STAR or snowflake type schema. To go back to the sales analysis example above, in a STAR schema the facts about…. [caption id="attachment_3264" align="aligncenter" width="293" caption="Example star schema about sales. "][/caption] Often a dimension will include redundant information…
