… oriented engines I used single table without joins, and with small (as for DW) datasize (…infinidb-early-alpha/). Addressing these issues, I took Star Schema Benchmark, which is TPC-H modification, and …’s blog http://infinidb.org/infinidb-blog/mysql-parallel-query-processing-of-ssb-queries-via-…
Post: Data mart or data warehouse?
July 15, 2010 By 13 Comments
…) must be joined to additional tables (item_category,category) to find the category. These are not as popular as star schemas because they… hash joins, bitmap indexes, table partitioning, parallel query execution, clustered tables and materialized views. These features make 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: Shard-Query turbo charges Infobright community edition (ICE)
May 6, 2011 By 22 Comments
…Query it is important to test complex queries involving joins and aggregation. A star schema is the most common OLAP/DW data …02 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
… star schemas. The problem is that MySQL doesn’t tend to perform well on a data warehousing workload. The nested-loop joins… 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: The MySQL optimizer, the OS cache, and sequential versus random I/O
April 28, 2008 By 17 Comments
… measured the performance on a join between a few tables in a typical star schema data warehousing scenario. In …. MySQL doesn’t want to choose this join order, so we’ll force it with STRAIGHT_JOIN: explain select STRAIGHT_JOIN …. +——-+———–+———–+———————————+…
Post: How to estimate query completion time in MySQL
April 22, 2008 By 14 Comments
… needed optimization. It was a fact table joined to two dimension tables — a classic 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: Intro to OLAP
July 12, 2010 By 9 Comments
…particularly OLAP (or online analytical processing) tools using MySQL and other free open source software. OLAP… STAR or snowflake type schema. To go back to the sales analysis example above, in a STAR schema… in the fact table that don’t join to dimensions are either considered degenerate dimensions …
Post: New OLAP Wikistat benchmark: Introduction and call for feedbacks
January 28, 2010 By 16 Comments
… Star Schema Benchmark got a lot of interest (links: http://www.mysqlperformanceblog.com/2010/01/07/star-schema…) sm FROM pagestat JOIN datesinfo di ON ( di.id=date_id ) JOIN projects p ON (p… data and run queries against available engines: MySQL MyISAM / InnoDB (to have reference results) InfoBright…
Comment: Analyzing air traffic performance with InfoBright and MonetDB
October 12, 2009 By 50 Comments
… dimension “tables” were actually views joining underlying base tables in order to make the warehouse schema accessible via Mondrian’s dimensional model… SQL (you’ll see a lot of star joins). The data volume is piddling though. For schema complexity, I’m not aware of… something that already has Mondrian set up with PostgreSQL or MySQL, we have an automated procedure for replicating that into LucidDB…
