Talk:Online analytical processing

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Older comments[edit]

What's the story about the text "Around 50% of Olap licences are never deployed"? -- Waveguy

A nice indicator of how tricky Olap is to set-up and use. TwoOneTwo

Reply to Jay - technically yes, in usage sometimes no. You can regard it as an affectation and change it if you want. Thanks for pointing up Waveguy's question TwoOneTwo

I think usage also should be given a priority. Can you show me an article (outside Wikipedia of course) where OLAP is mentioned as Olap ? I couldn't find any instances from Google because Google searches are case-insensitive. Jay 08:18, 3 Oct 2003 (UTC)

The article states that Oracle Express was released in 1970. This cannot be true as Oracle did not exist as a product until 1979. Could this be a typo for 1990? Geoff97 22:32, 2 Jan 2004 (UTC)

Express has been around since about 1970 (with IRI) but was only taken over by Oracle in about 1995. -- TonyP 13:17, 23 Jan 2005 (UTC)

The history I've heard was that it was originally an MIT research project in the early 70s (PhD project maybe?) and was then productized. I believe IRI acquired it sometime in the mid to late 70s - previously I believe it was owned by a company called Multidimensional Systems or something? Cchiappa 22:02, 11 January 2006 (UTC)
Express was started at MIT, the beginning is fuzzy. Eventually, it was commercialized by a Boston company called MDS (Management Decision Sciences) which sold it in the 70's and 80's on a Prime minicomputer. Express was more popular in marketing department than finance departments, who were more partial competitors IFPS and Comshare. MDS was acquired by IRI in the late 80's. IRI sold it to Oracle in about 1996 when it was the #1 OLAP tool and proceded to run it into the ground. By the way, this whole article, and the one on Business Intelligence, is a mess. Neil Raden 05:18, 20 September 2007 (UTC)

I would dispute the definition of OLAP as given here. I would guess Codd's paper has to be the true definition since it coined the term. However, multi-dimension data and indexes were in use long before that paper. It really is a different way of indexing/accessing the data (as distinct from relational), and sometimes even different storage too (as in MOLAP). It is not specifically a snapshot of any relational database. Also, products such as Holos demonstrated that multi-cube and joining were just as applicable to OLAP as SQL data -- TonyP 14:45, 25 Jan 2005 (UTC)

Holos was, I guess, the first ROLAP product. It was fatally flawed in so many ways, though. Anyway, whatever definition you use, OLAP is characterized by interactive navigation through data, performing calculations on the fly without specifc instructions. In other words, not adding up things that are not additive, like %'s, or headcounts or balances over time. Their basic orientation is hierarchical attributes describing numerical values. Codd didn't come up with the rules, he was paid by Arbor Software to publish them and many feel he disgraced himself in the process. Neil Raden 05:18, 20 September 2007 (UTC)

Actually, just for the archive, Holos was never a ROLAP product in the true sense. It was primarily a MOLAP, and secondarily a HOLAP ('hybrid'). Unfortunately, it was widely misunderstood and all-too-often compared against pure query engines --TonyP (talk) 20:27, 8 April 2009 (UTC)

Market Shares - Copyrighted information[edit]

The market share data that comes from OLAP Report is copyrighted by "Optima Publishing Ltd". I'm not sure if the use here qualifies as Fair use.

The page says the following: "This is copyright material. You can make brief references to it freely, with attribution, but not reproduce large sections or the entire article without permission from the publisher. You are free to link to this page without permission." I assumed that sdfsdf copying the names of the companies and their market shares would fit under "brief reference" and "not reproduce large sections". Should we contact the publisher to clarify this ? Wikiolap 20:17, 12 January 2006 (UTC)
I missed that note on the page. I would think it qualifies as brief.

Merging FASMI[edit]

I think it is OK to leave FASMI at its own page and not to redirect to OLAP page.

Except, with all due respect to Nigel Pendse, no one in the industry Uses FASMINeil Raden 05:18, 20 September 2007 (UTC)

OLAP Operation Types[edit]

It would be nice to have a listing of the OLAP operation types (e.g. slice/dice, roll-up, drill-down, pivot, etc.) I don't have a good definition of them in my head so I came here to refresh. I think they're one of the key properties of OLAP, no?

--Michaell 04:19, 13 October 2006 (UTC)

"See "OLAP cube" Kgrr (talk) 11:12, 17 March 2008 (UTC)

Examples[edit]

It would be nice to have some examples, of measures and values, for instance. It is a little difficult for non-experts to understand without them.

--Gilliancs 19:32, 17 February 2007 (UTC)

I agree. I found this introductory article to be very useful. Read under "OLAP cube examples".Konrad Dramowicz (2005-15-01). "Creating and Manipulating Multidimensional Tables with Locational Data Using OLAP Cubes" (in English). Directions Magazine.  Check date values in: |date= (help)
Kgrr (talk) 19:53, 29 February 2008 (UTC)

Change Name[edit]

Recommend changing acronym name of article to full name: "Online Analytical Processing", and redirect "OLAP" to this page. This is parallel in construction with the "Online Transaction Processing" article. Comments? SqlPac 14:52, 17 May 2007 (UTC)

I prefer to keep things the way they are, where Online Analytical Processing redirects to OLAP. Wikiolap 15:01, 17 May 2007 (UTC)
That being the case, then perhaps Online transaction processing should redirect to OLTP. I'm not too concerned with which way it's done - I'm more concerned with giving these topics parallel construction. I'll drop a line on the OLTP talk page and recommend the reverse of this change recommendation and see what people think then. Thanks! SqlPac 16:25, 17 May 2007 (UTC)
I believe the current name does not comply with "Avoid the use of abbreviations, including acronyms, in page naming unless the term you are naming is almost exclusively known only by its abbreviation and is widely known and used in that form." Wikipedia:Naming_conventions#Prefer_spelled-out_phrases_to_abbreviations, and it is OLAP that should be moved. -- Beardo 01:46, 15 June 2007 (UTC)
That was my original thought as well, but with an objection on the table I don't have consensus. It looks like it was already done anyway, so until someone complains I guess it's good to go. Thanks. SqlPac 04:54, 15 June 2007 (UTC)
It should stay this way. Consider if the acronym OLAP is used somewhere else, then it will become a disambiguation page. It's very likely though that Online Analytical Processing will remain unambigous.Kgrr (talk) 20:02, 29 February 2008 (UTC)

Bibliography[edit]

Daniel Lemire (2007-12). "Data Warehousing and OLAP-A Research-Oriented Bibliography" (in English).  Check date values in: |date= (help)

WP:EL[edit]

Wikipedia is not a collection of links. The external references section becomes an open invitation to piles of SPAM if we are not careful. I will move good sources (Journal articles, books, and published magazine articles.) and delete the rest. I have copied the existing external references here in case there is a dispute:

(This link now (2008-03-06) resolves to http://www.oracle.com/technology/index.html, so don't expect to find Codd's paper there.) (found proper reference)

I will help you get the article in shape. We just need to follow the guidelines. Kgrr (talk) 13:21, 17 March 2008 (UTC)

In essence, each action of slicing and dicing is equivalent to adding a "WHERE" clause in the SQL statement.[edit]

... is outright wrong for Dicing. Dicing refers to orienting the hypercube in another way, which basically means, that the usual matrix display changes axes, which often implies a different list of columns.

Slicing (setting filters), is equivalent to adding a "WHERE" clause. dicing is equivalent to changing the selected columns. — Preceding unsigned comment added by 80.130.29.135 (talk) 20:06, 7 June 2012 (UTC)

Proposed Merger: Merg OLAP Cube into this page[edit]

Merger proposal[edit]

I am proposing that OLAP cube be merged here. There is significant overlap to the extent that some of the other langauge Wikipedias are wikilinked to one or the other as if they were the same thing. I am probably doing this wrong, but I am more of a language/ general knowledge person, I don't really get too involved with the WP guts, so please, those who are better at this kind of thing, please weigh in. Best regards, Rui ''Gabriel'' Correia (talk) 18:59, 15 August 2012 (UTC)

Proposed Clarification[edit]

The terms measurement (often called a metric) and dimensions seem to be used differently here than they are in mathematics. The concepts of a measurement (metric) and a dimension are interchangeable in mathematics. Any measurement can be treated as a dimension of any hypercube within any vector space. This article makes a distinction between these two terms that should be clarified to help the formal mathematics students among the readership.

In mathematics there is often a distinction between independent and dependent variables, dimensions, or metrics. The terms range (set of possible values of the independent variable) and domain (set of possible values of the dependent variable) of a function or system is often used in mathematics as well. This may be what is intended for the dinstinction between measurement and dimension in this article. It seems that wherever this article says "measurement" the mathematics reader should think "dependent variable or dimension". And whereever the article says "dimension" the mathematics reader should think "independent variable or dimension"

Am I mistaken? Would it not be helpful for me to clarify the ambiguous business language of this article with more precise mathematics terms? — Preceding unsigned comment added by 70.66.13.60 (talk) 16:44, 1 September 2012 (UTC)

I'm not sure where the specific references are that you're mentioning. However, "measures" is usually a dimension consisting of multiple fields, each of which is a distinct measurement of something. Products vary in how similarly or differently they treat their dimensions. For instance a "time" dimension usually has properties that do not apply to others - such as an implicit ordering of the fields. The Holos product used to use the term "orthogonality" in its marketing since (at the time anyway), it treated its dimensions in an unusually consistent fashion. TonyP (talk) 14:06, 2 September 2012 (UTC)
Business jargon can be a bit quirky but, from a mathematical perspective, you can think of "measures" as the dependant variables. The relationship between variables and dimensions can be a little confusing:

In a typical cube there is one dimension of "measures" in which each of the dependent variables is an "element" of the dimension, and each independent variable is a separate dimension in which the "elements" of the dimension are the discrete values which the variable can take. E.g., in a meteorological table, dependent variables like Rainfall or High_Temperature would each be "elements" of a single "measures" dimension, and independent variables like Date or City would each be a dimension unto itself, with discrete values like January or Paris as "elements". ~ Ningauble (talk) 18:47, 2 September 2012 (UTC)

Merge discussion[edit]

ROLAP, HOLAP, MOLAP and OLAP cube are all subtopics of OLAP. Propose merging them all into the OLAP article as subtopics. The OLAP article is not overly long and these other articles are not particularly long either. It would benefit all articles to clean them up and merge. SqlPac (talk) 03:29, 28 February 2013 (UTC)

Merge *OLAP, leave OLAP Cube: Indented line I recently added the advantages and disadvantages of ROLAP to the ROLAP section. Do we like this? If so, I can continue with the rest of them but I wanted to see thoughts on this. I feel ROLAP, HOLAP, and MOLAP don't need their own respective articles but OLAP cube does. Augbog (talk) 23:08, 28 February 2014 (UTC)
Merge All: I think it makes sense to merge them. They are all short. The con arguments don't totally make sense to me... voyage of discovery? No offense but surely one doesn't need to click extra clicks to go on a voyage of discovery? Vcrs (talk) 03:55, 3 May 2014 (UTC)
Leave All: Its better to be specific than merging all information under one title — Preceding unsigned comment added by 203.215.173.136 (talk) 12:03, 15 March 2013 (UTC)
Merge *OLAP, leave OLAP Cube: Since the term "OLAP Cube" and/or "the Cube" is a very popular term, maintaining a separate entry for "OLAP Cube" would facilitate easier access by non-technical users. The reader could then move to the more general from the specific, if needed.24.33.150.67 (talk) 14:00, 12 May 2013 (UTC)
Leave All: As per the comment above OLAP cube is a very popular term. Indeed it is what I searched for today when I found this article. Having read about OLAP cubes I wanted some more general information so I went to the Online Analytical Processing page and discovered other forms of OLAP. If you try and cover all of this in one big article it may deter people from reading it rather than entering the voyage of discovery that browsing from page to page does. Deevincentday (talk) 12:09, 13 November 2013 (UTC)
Merge *OLAP, leave OLAP Cube: Agree with what other people have said. Definitely OLAP Cube seems like a topic that can stand on its own. I do however think that ROLAP, MOLAP, and HOLAP deserve to be merged in since they are simply subtopics under OLAP. Augbog (talk) 23:00, 28 February 2014 (UTC)
Leave All: I agree that the shouldn't be merge those are different techniques and way of doing OLAP — Preceding unsigned comment added by 64.229.91.225 (talk) 01:15, 31 July 2013 (UTC)
Merge *OLAP, leave OLAP Cube: Merging would allow a better page that covers them all with comparisons of advantages and disadvantages of all approaches. There's no advantage to keeping them apart, and it makes any comparison between them harder. (also cleaned up the vote list here: apologies if I have misrepresented anyone's position.) DewiMorgan (talk) 21:43, 7 June 2014 (UTC)

Agree with merging the articles, but leaving cube as stand-alone. Can't imagine someone reading OLAP topic and not wanting to view the MOLAP, HOLAP, ROLAP topicsCtatro (talk) 19:07, 5 December 2014 (UTC)

  • oppose merges. Merging "because the article is not overly long" is never a good idea when the topic is so big. Even when wikipedia is yet to cover it as fully as it deserves.
Also cubes are not an essential feature of all OLAP. Maybe they ought to be, but plenty of people are still trying to do OLAP on top of an ERD-ed OLTP database. 80.254.147.116 (talk) 10:59, 29 August 2014 (UTC)
  • Merge *OLAP, leave OLAP Cube. Online Analytical Processing is a very broad subject that should include MOLAP, HOLAP, ROLAP, etc. An OLAP Cube is a very specific article. This article is already very big on its own and would eventually be split-out of the more abstract article on Online Analytical Processing. (Original author of OLAP cube) 50.135.204.13 (talk) 20:37, 3 February 2015 (UTC)

Split out "Multidimensional databases"?[edit]

Multidimensional databases seem to be a larger subject than OLAP in database models. -- Beland (talk) 01:08, 5 March 2013 (UTC)

Er, we also have Dimensional database as a redirect to Data warehouse, and they sound very similar. -- Beland (talk) 01:25, 5 March 2013 (UTC)