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2
votes
1answer
19 views
+100

Best way to capture historical changes between levels in a dimensional hierarchy

What is the cleanest way to capture changes between levels in a dimensional hierarchy? I have the dimensional hierarchy [Area] > [Region] > [Location], where Area is the parent to Region and Region ...
1
vote
1answer
54 views

SSAS Hierachies duplicates when browsing

The dimensions in the cube are giving us duplicates, there is no error while processing the cube, but when the cube is browsed we could see duplicates. There is a hierarchy in our dimension, the ...
0
votes
0answers
75 views

SSAS MD dimension joins to same table twice (but processing fails as attribute has 2 names for same ID)

My cube has a product dimension, and each product has an "availability" status attribute. In the database, SellableItemAvailabilityId in DimSellableItemVersion (which contains products) joins to Id in ...
3
votes
2answers
135 views

Cube with 2 measure groups (with different relationships to dimensions) returns too many dimension members in reports

I have a cube that contains stock-take data from retail operations. It has 2 measure groups - one containing the number of stock units counted in each stock-take batch (which is related to the ...
1
vote
2answers
63 views

Ordering of a dimension in sql server datawarehouse

Built and deployed a simple cube with a date dimension. The dimension has things like day of month. How do i sort it? it always shows in the reports as 1, 10, 11, 12, ... 19, 2, 20, 21 Design. ...
1
vote
1answer
30 views

What if the lowest granularity level can legitimately be null?

I have a normalized database that I'm going to be using as a source for a dimensional data store; one of the facts I'm collecting is Orders, the normalized schema looks roughly like this: However ...
6
votes
1answer
75 views

Designing a dimensional DB off a normalized source that already implements SCD's

I have built an SSIS ETL to integrate various data sources (one from MySQL, two from SQL Server) into a single SQL Server relational and normalized database, which I've called [NDS]. The SSIS ETL ...
4
votes
1answer
72 views

How do I make a nullable “parent” hierarchy level?

I'm setting up my first dimensional database with SSAS, and I have this [Materials] dimension that needs a hierarchy that goes something like this: [PriceCode v] --> nullable Price Code ... ...
4
votes
1answer
901 views

How can I get the measures of the last month with MDX?

I would like to get the values of the measures of the previous month. That's what I have: SELECT [Measures].[Recuent distinct] ON ROWS, TAIL(NonEmptyCrossJoin([Dim Date].[Calendar].[Month ...
5
votes
0answers
28 views

What Database is optimized for 4d data layout? [closed]

I need to store 4d data points inside a virtual 3d world (position+date+data value). I have a lot of data layers > 250 (wind direction, sea temperature, terrain type, etc). Sources of my data layers ...
2
votes
2answers
204 views

When to choose an attribute vs. a new dimension?

I am fully aware of what is a fact, attribute and dimension. However, I'm quite confused to which traits I should choose for dimensions vs attributes of that dimension. For instance, I'm building a ...
2
votes
0answers
51 views

Column Store Indices versus Dimensional Tables

I have a Data Warehouse and want to think ahead one year when I may get a database update allowing me to use column store indices. My dimensional tables are mostly junk dimensions containing columns ...
2
votes
1answer
43 views

Duration measure in fact table

I have a fact table with the user reservations with StartDate and EndDate. I am thinking what is the proper way of serving the duration queries in the reports. Should I calculate DurationDays and ...
0
votes
1answer
45 views

Dimensional Model for inheritance in dimensions

How are dimensions typically modeled in a dimensional model if one dimension logically inherits from another dimension? For example, assume I have an Employee dimension and a Driver dimension, where ...
1
vote
0answers
90 views

ETL flow in Fact tables

I've got a simple theoretical question... If we discuss the principles, elements, design and implementation of a typical ETL flow for a dimension table then, in my understanding, (in short) I'd say ...
1
vote
1answer
1k views

Dimensional Modeling and ETL in Redshift

I have been researching Amazon's Redshift database as a possible future replacement for our data warehouse. My experience has always been in using dimensional modeling and Ralph Kimball's methods, so ...
1
vote
0answers
97 views

how many fact tables do I need given I want to build an OLAP for Quotation Line Item and Purchase Order Line Item report?

My client wants a report that looks something like this on a daily basis. +---------------+-------------------------+-----------------+---------------------+-------------+ | ProductNumber | ...
0
votes
1answer
321 views

What to do when facts change frequently in a star schema for data warehouse?

I have a Quotation Management system that I built as a CRUD web app. Over time, I realized I need to improve it so that management can have their reports. Hence I studied the Kimball method of data ...
1
vote
3answers
139 views

Data Warehouse measures without a corresponding dimension

I have an operations database that contains this table: salesQuality salesPrice salesCategory According to my business requirements, the salesQality and salesPrice are measures. However, ...
0
votes
0answers
93 views

Which is the best way for selecting dimension attributes while creating a dimension?

I'm a newbie to SSAS OLAP so please apologize me if it was a silly question but surely I need suggestions. I would like to make clear some concepts which was confusing for me. Let us consider five ...
1
vote
1answer
108 views

Should I create a Factless Fact Table or Denormalise my table

I am creating a data warehouse from a store database and I have a question regarding the design of my dimensions and facts. In the store database a table exists for Person, Person_Address and ...
0
votes
1answer
32 views

Conformed Fields or Snowflake? - Shop and Customer Location

I have shop dimension and customer dimension which both has location information. Should I create location dimension to correlate shop location and customer location? I believe this one is called ...
1
vote
2answers
72 views

Dimension for Product Properties based on Product Type - Sparse Dimension?

I am creating dimension of product properties for sales facts. Property of product depend of product type. For example: - Type = smartphone. Properties = model, OS, size - Type = book. Properties = ...
8
votes
2answers
2k views

Is my understanding of Fact table granularity correct?

Myself and another DBA at our company are tasked with reviewing a database design that a vendor has developed for us. The vendor has said they use Kimball as the basis for their design. (NOTE: I am ...
2
votes
1answer
52 views

Modeling Conversion Events in a Data Warehouse

How should I model conversion events? For instance, if a sales opportunity goes from "stage: prospecting" to "stage: validating", should that be treated as a changing dimension, or a conversion event ...
1
vote
2answers
272 views

Business Logic in Data Warehouse

my question is: Should business logic be stored in the data warehouse data store? Or should it only exist in the reporting applications? To give a more concrete example: In the CRM operational ...
0
votes
2answers
247 views

Database design for tracking referral dollars and referred dollars

Dropbox has a great referral incentive program that gives a storage bonus based on whether a person is referred to Dropbox or refers others to Dropbox. What data base design is good for managing ...
1
vote
2answers
272 views

Dimension or Degenerate Dimension?

I am taking a course on data warehousing. Currently, I am reading through Ralph Kimball's Data Warehouse Toolkit. I understand that a degenerate dimension is a dimension key that is stored in a fact ...
0
votes
1answer
335 views

Constellation Schema; Relationships between fact tables

What are acceptable types of depedendcies between facts in a multiple-fact schema? Conceptually talking, As you know a Multi-Dimensional Model may have multiple facts (like in a constellation ...
2
votes
1answer
984 views

Dealing with measure groups of different granularity

Let's say I have a simple data warehouse with the following fact tables: FactPurchase: one row per property purchased, with purchase amount, value, etc. FactMonthlyStatus: one row per property, per ...
1
vote
2answers
713 views

To normalize or not to normalize for few distinct values

Assuming in a Postgres database, you have a table called party, which can have less than 5 well-defined party_types such as 'Person' or 'Organization'. Would you store the party_type in the party ...
2
votes
3answers
536 views

How to solve multidimensional data relationship

I'm having a problem, that I could solve programmatically, but for my personal (test) project I'm trying to see if I can fix it in the relational model. Imagine a complex fashion product Pants with ...
0
votes
0answers
197 views

Datamodel design for multiple roles, country access

I am in the process of creating a data model for the below scenario there will be two hierarchies a) dept hierarchy (emp -> team -> dept -> branch) b) sales hierarchy (emp -> marketing manager -> ...
0
votes
1answer
339 views

Type of Foreign Keys for a Dimensional Model Fact Table?

I've been reading about dimensional models, and in particular fact tables, but I haven't really seen one in action (i.e. the actual content), just diagrams of the table structures and column names ...
1
vote
1answer
806 views

Modeling staff dimension in data warehouse

I need to write a data warehouse diagram. I've got a problem with staff area. I have to store a information about workers details like name, age etc., and workers job time and agreement details like ...
0
votes
1answer
178 views

BI development in Microsoft BI

I need to learn how to create a dimensional modelling for an organisation that do not has a BI tool and BI model. Where can I learn more about BI development that should be used in a company? IT's ...
8
votes
3answers
6k views

Datawarehouse Design: Combined Date Time dimension vs. Separate Day and Time dimensions and timezones

We are just starting design for a new data warehouse and we're trying to design how our date and time dimensions will work. We need to be able to support multiple timezones (probably at least GMT, ...