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Scripted plug-ins in LucidDB and Mondrian
I saw a demo last week of scripted user-defined functions in LucidDB, and was inspired this weekend to add them to Mondrian.Kevin Secretan of DynamoBI has just contributed some extensions to LucidDB to...
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Removing Mondrian's 'high cardinality dimension' feature
I would like to remove the 'high cardinality dimension' feature in mondrian 4.0.To specify that a dimension is high-cardinality, you set the highCardinality attribute of the Dimension element to true....
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Roll your own high-performance Java collections classes
The Java collections framework is great. You can create maps, sets, lists with various element types, various performance characteristics (e.g. if you want O(1) insert, use a linked list), iterate over...
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Yellowfin BI release 5.2 moves to olap4j
According to their press release, Yellowfin BI version 5.2 "includes a significant OLAP overhaul, with the introduction of OLAP4j and support for PALO, BW as well as enhanced connectivity for SQL...
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Real-Time Seismic Monitoring
Marc Berkowitz wrote a blog post describing an application of SQLstream to power a seismic monitoring project that is a collaboration between several leading research institutions.The project is...
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How Mondrian names hierarchies
You may or may not be aware of the property mondrian.olap.SsasCompatibleNaming. It controls the naming of elements, in particular how Mondrian names hierarchies when there are multiple hierarchies in...
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Changes to Mondrian's caching architecture
I checked in some architectural changes to Mondrian's cache this week.First the executive summary:1. Mondrian should do the same thing as it did before, but scale up better to more concurrent queries...
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olap4j releases version 1.0.1, switches to Apache license
I am pleased to announce the release of olap4j version 1.0.1.As the version number implies, this is basically a maintenance release. It is backwards compatible with version 1.0.0, meaning that any...
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Auto-generated date dimension tables
It seems that whenever I have a cross-continent flight, Mondrian gets a new feature. This particular flight was from Florida back home to California, and this particular feature is a time-dimension...
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How should Mondrian get table and column statistics?
When evaluating queries, Mondrian sometimes needs to make decisions about how to proceed, and in particular, what SQL to generate. One decision is which aggregate table to use for a query (or whether...
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"Big Data" is dead... long live Big Data Architecture
Now that just about every data-management and business intelligence product claims that it handles "Big Data", the term is approaching zero information content.So, I'm shorting the term "Big Data". In...
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Data-oriented programming for the rest of us
I have been a fan of LINQ for several years (my Saffron project covered many of the same themes) but I've had difficulty explaining why it isn't just a better Hibernate. In his article “Why LINQ...
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A first look at linq4j
This is a sneak peek of an exciting new data management technology. linq4j (short for "Language-Integrated Query for Java") is inspired by Microsoft's LINQ technology, previously only available on the...
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From the ashes of the database revolution...
With NoSQL and Hadoop, the database world has undergone a revolution. The fighting reached its peak a couple of years ago, but things have calmed down since, and now is a good time to take stock of old...
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Pesky quoted identifiers in SQL
The SQL that Mondrian generates is, until now, different than the SQL that most people would write by hand. Most people don't use spaces or punctuation in table and column names, and don't enclose...
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Mondrian in Action
I am delighted to announce an upcoming book all about Mondrian, called "Mondrian in Action". Some chapters are available in electronic form now, and the final print version is scheduled to hit the...
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Mondrian in Action in Action
I couldn't resist. When the Mondrian in Action book is published in the spring, it will look something like this...Artist's conception of the upcoming bestseller, "Mondrian in Action"
View ArticleExplaining holidays to a 3 year old
Your birthday involves presents and cake. The day after your birthday you are allowed to say "I am x", where x is the number of candles on your cake.4th of July is the birthday of our country, which is...
View ArticleAnnouncing Lingual
The last few months, I've been collaborating on a project with Chris Wensel, the author of Cascading. Last week we announced Lingual, an open source project that puts a SQL interface on top of...
View ArticleOptiq latest
Optiq has been developing steadily over the past few months. Those of you who watch github will know most of this already, but I thought I'd summarize what's been going on.(This post originally...
View ArticleNeed help
I was amused by this note I just received via email.Subject: Need helpTo: jhyde@users.sourceforge.netFrom: <retracted>Respected Sir, we are doing a final year project as Student Data warehouse...
View ArticleGathering requirements for olap4j 2.0
It's time to start thinking about olap4j version 2.0.My initial goal for olap4j version 1.0 was to decouple application developers from Mondrian's legacy API. We've far surpassed that goal. Many...
View ArticleEfficient SQL queries on MongoDB
How do you integrate MongoDB with other data in your organization? MongoDB is great for building applications, and it has its own powerful query API, but it's difficult to mash up data between MongoDB...
View ArticleImprovements to Optiq's MongoDB adapter
It’s been a while since I posted to this blog, but I haven’t been idle. Quite the opposite; I’ve been so busy writing code that I haven’t had time to write blog posts. A few months ago I joined...
View ArticleTable macros
Table macros are a new Optiq feature (since release 0.6) that combine the efficiency of tables with the flexibility of functions. Optiq offers a convenient model for presenting data from multiple...
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