… a typical OLAP workload features a low number of concurrent queries which each examine large amounts of data. Since a single query is….737620115286.07981824874886.0321369171143 The reason 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…
Post: New OLAP Wikistat benchmark: Introduction and call for feedbacks
January 28, 2010 By 16 Comments
… queries). You can see details on our Percona Wikistat benchmark Wiki. I have next goals with proposed benchmark: Compare engines in OLAP queries for planning, predicting growth, analyzing access patterns to wiki pages, draw trends. Compare engines in statistical queries for end…
Post: Intro to OLAP
July 12, 2010 By 9 Comments
… to OLAP and business intelligence. (this post) Identifying the differences between a data warehouse, and a data mart. Introduction to MDX queries… have to write queries or drag and drop a report together in order to analyze multidimensional data using an OLAP tool. Data…. MDX is a query language that looks similar to SQL but is actually very different. Olap4j is an OLAP interface for java…
Post: Shard-Query turbo charges Infobright community edition (ICE)
May 6, 2011 By 22 Comments
… of Shard-Query it is important to test complex queries involving joins and aggregation. A star schema is the most common OLAP/DW…’t be added. Q9 is an example of such a query. . Query details: — Q1 SELECT DayOfWeek, count(*) AS c from ontime_fact… machines, scaling out to improve query response times significantly. These queries are a great test of Shard-Query features. It is currently approaching…
Post: Data mart or data warehouse?
July 15, 2010 By 13 Comments
… database software supports hash joins, bitmap indexes, table partitioning, parallel query execution, clustered tables and materialized views. These features make working…-dimensional query language. Mondrian turns MDX into SQL, so we’ll also look at the kinds of queries which are generated by OLAP…
Post: Testing MySQL column stores
August 16, 2010 By 15 Comments
…” for typical OLAP analysis queries. These tests were intended to approximate what would happen if you ported a MyISAM OLAP application to ICE… noted that the second set of tests included 29 different queries, some of which were provided by Infobright and others which… to get accurate results for all of the queries on InfiniDB. In particular the query “select count(*) from carsales.sales_fact” when…
Comment: Intro to OLAP
August 8, 2010 By 9 Comments
… query about CUBE and OLAP (whether MOLAP,ROLAP,HOLAP), what’s the difference between CUBE and OLAP? Looks like when we talk about OLAP…
Comment: Should you move from MyISAM to Innodb ?
January 28, 2009 By 53 Comments
… choice than MyISAM. Because I’m that guy who develops OLAP system. My DBs are very small compared to the mentioned… cases – mysqldump of the largest DB is only 550M. But queries upon data can run for seconds and even tens seconds… in the two biggest tables (which participate in almost every query) reached 300K and 50K, performance issues are visible. Data updates…
Comment: High-Performance Click Analysis with MySQL
December 23, 2008 By 13 Comments
… data mining the raw data from MySQL slaves into OLAP cube and then query the cube from the application, leaving MySQL to… the application while the reporting is on different set of OLAP servers.
Comment: Shard-Query adds parallelism to queries
February 24, 2011 By 16 Comments
… cluster-db / shard-query with mondrian for doing olap cubes? Also, how hard would it be to modify shard-query to work with… sqlite3 dbs running on a variety of platforms and doing queries against sqlite3 using cluster-db.. The load/performance for doing… be ok if i partition the tables often enough, since queries would be read-only, and the benefit would be to…
