… source data into the warehouse schema. Another important aspect of the definition is aggregation. A data warehouse is usually used to summarize data over years… data warehouse, but they also build data marts for OLAP analysis from the warehouse data. A different approach is to build a relational warehouse from multiple data…
Post: Intro to OLAP
July 12, 2010 By 9 Comments
… business intelligence. (this post) Identifying the differences between a data warehouse, and a data mart. Introduction to MDX queries and the kind of… difference between data marts and data warehouses. The former are usually used for OLAP analysis, but they can be fundamentally related to a warehouse.
Post: MySQL Limitations Part 4: One thread per connection
October 27, 2010 By 14 Comments
… lovely to have those things, if you’re running a data warehouse on MySQL, and in some cases for other uses too… startup cost for the query). But MySQL isn’t a data warehouse DBMS first and foremost. It’s a general-purpose OLTP… can be used for tons of other things such as… data warehousing. But it isn’t a Netezza or Paraccel, and…
Comment: The case for getting rid of duplicate “sets”
May 17, 2011 By 2 Comments
Welcome to data warehouse summary/aggregate/fact tables (just to name them properly).. http://en.wikipedia.org/wiki/Aggregate_(Data_Warehouse)http://en.wikipedia.org/wiki/Fact_table
Post: High-Performance Click Analysis with MySQL
December 22, 2008 By 13 Comments
… expensive to solve. Start with the granularity of your data. What data do you need to make your business run?Â… aggregates, you’re exposed to that bad data again. Any inconsistencies in the atomic data tend to get magnified as it gets… You What you’re really doing here is building a data warehouse. So you may think you should use traditional DW…
Post: Shard-Query turbo charges Infobright community edition (ICE)
May 6, 2011 By 22 Comments
… OLAP/DW data model, since it typically represents a data mart. See also: “Data mart or data warehouse?”. As it is the most common data model… containing all of the data. Before loading, there was approximately 23GB of data. After loading, ICE compressed this data to about 2GB. The…, each shard has about 335MB-350MB of data (23GB raw data, compressed to about 2GB total data. then spread over six servers). Due…
Post: How Percona does a MySQL Performance Audit
November 24, 2008 By 17 Comments
… hearing you say “we are a SaaS hosted application for data mining stock market transactions,” or whatever the case may be… compare it against the server’s variables or whatever other data I need, and write something instructional to the client about… operate. For example, if the workload is a star schema data warehouse, it is important to know a lot about the I…
Post: How many partitions can you have ?
December 5, 2009 By 18 Comments
… recently. The customer dealing with large MySQL data warehouse had the table which was had data merged into it with INSERT ON DUPLICATE…) using bulk insert statements – 1000 rows in each. Loading the data was taking 9 seconds for 1 partitions, 10 seconds for… is per row overhead. This test gives other rather interesting data point – it looks like updates in Innodb for CPU bound…
Comment: Quick comparison of MyISAM, Infobright, and MonetDB
September 30, 2009 By 30 Comments
…). It is another open-source RDBMS that is specialized for data warehouse queries. John spoke about it at the Percona Performance conference… per column for each block of a database file (data packs or data pack nodes in Infobright) is also used by Netezza… it). Although Infobright does more this storing aggregated values per data pack. Monty also spoke at the MySQL Conference about this…
Comment: Data mart or data warehouse?
December 16, 2010 By 13 Comments
…A normalized data warehouse schema might contain tables called items, categories and item_category. … large number of joins when many dimensions are involved. A data mart would collapse all of this information into an item… single column? (Yes, I have exactly this problem in my data mart with SCD, and it requires some brutal joins). Your…
