Questions tagged [data-warehouse]
A database system optimised for reporting, particularly in aggregate. Often, but not always implemented using a star schema.
380
questions
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How to correctly define foreign keys to heterogenous dimensions in fact table?
Question
What is the best practice for defining foreign keys in a fact table to multiple different and mutually-exclusive dimension tables?
Example Case
Business process
I am creating a ...
0
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1answer
24 views
Deciding what values should be used in a data warehouse dimension?
I'm beginning to look at data warehousing and I'm coming across examples where, for instance, we have check payment transactions. I understand that this should be the "fact" and we would have ...
0
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1answer
15 views
In a data warehouse, should a measure be based on a fact or a dimension?
Let's say there is a data warehouse created from a shop data. A fact is a single purchase of a product. There is a dimension that describes a customer.
There is a need to create a measure that ...
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0answers
19 views
Implementing data warehouse on the cloud [closed]
I need to implement a data warehouse on the cloud for a mid-sized company. The database size will be around 200 Gb.
My options are (so far):
AWS with its database Redshift
Azure with its database ...
0
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0answers
12 views
Trying to do a fact and dim table in Sql
so far this is what i have code wise, but im getting an error 1239 . Is it not referencing something correctly .
CREATE TABLE CustomerDim
(
C_CustomerID_Cu INT(10) NOT NULL,
...
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0answers
34 views
Star schema with both many-to-many relations and inheritance
The problem
I am trying to make a star schema of the following situation, concerning transactions on a stock market. I have summarized the scenario here:
Each transaction traded on the market has
1 ...
2
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2answers
79 views
Handling Big Data
I have a MySQL database that will have 2000 new rows inserted / second. These rows indicate the value of a sensor at that particular moment.
The plan is to get this data into graphical ...
1
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0answers
26 views
Store email in a separate Dimension or in a Degenerate Dimension?
I just started learning about dimensional modeling and I am creating a star to analyse email newsletter signups for an online business.
I have a fact table that records the signups and links to a ...
0
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0answers
22 views
implementing one to many relation between 2 dimensions in dataware house
I am designing a Dataware house for the Stackoverflow job section. I have two dimensions: job opportunity and company. every record of job opportunity is referenced to only one record of company ...
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0answers
37 views
DataWarehouse with MS SQL Server by Schemas
I am planning to create a DataWarehouse with Microsoft SQL Server.
My idea is to create "cubes" of data. To achieve this I created schemas for every department and the idea is that every department ...
1
vote
2answers
74 views
Strategies/Resources for implementing data lineage in an ETL process?
I'm struggling to articulate my need here.
I've been tasked with developing a significant ETL process dealing with warehouse item costs in a major grocery chain using the full Microsoft Stack.
I'd ...
2
votes
1answer
188 views
What's the best way to concatenate a multi-column foreign key?
We are expanding our data warehouse to include a new source system. In the new system, we want a single column for a primary key, but in the old system it's two columns.
For exmaple:
create table #...
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0answers
39 views
How to generate queries for Star Schema Benchmark SSB?
After generating 1 Gigabit of the Star Schema Benchmark available via https://github.com/Kyligence/ssb-kylin
How to generate for exemple 1000 sql query to execute them on postgreSQL and sql server ...
1
vote
2answers
46 views
How does Data Warehousing work in reverse? [closed]
I've made many researches about data warehousing to learn more about it and I think I've grasped the idea. But I've read in an article or two that data warehousing allows you to do analysis on data ...
0
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0answers
22 views
Takes several hours to commit data on my data warehouse what seems for only one table
I have a data warehouse which runs several jobs during the night in order to update data.
Background and job execution(s) setup
One of these jobs updates the FactSale table consisting of the sales. ...
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0answers
19 views
How to handle multiple changing ID's for a single person
I have a company with a single party table containing Member ID(the primary key), Subscriber ID, Member Sequence ID, Legacy ID, and a myriad of other identifiers from random source systems. Because ...
2
votes
2answers
374 views
Which DB for 1 table with 100 Million rows per year? [closed]
I've a questionnaire with 70 questions and need to store the answers.
Problem: it's 100 Million records per year.
I've experience with different types of storages, but never had to deal with these ...
6
votes
2answers
804 views
What is the best option for High availability on a data warehouse?
I have a customer who have an existing 1.5Tb data warehouse and are currently planning for a complete refresh of the DW on a new environment. Their infrastructure manager has organised 2 servers with ...
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0answers
40 views
Dimension attribute with one-to-many relationship
I have a request for an attribute in a dimension that has a one-to-many relationship with the lower level of the dimension.
Here is the case:
Dimension: Employee
Attribute: Immatriculation
I have ...
0
votes
1answer
44 views
Aggregating Multiple COTS Databases into a Data Warehouse or similar for Reporting
I am sure this is a very basic question, so I apologize, but I've read lots of articles and done a lot of google searches and have not found any leads for this particular challenge I am looking to ...
1
vote
1answer
36 views
How do you partition an events table by a time based off the datediff(Lag,time)?
I am not sure how really to ask this question as i have never come across such grouping/ partitioning before.
Basically i have an events table with 50 million rows that give me a timestamp, user, ...
0
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1answer
18 views
How to model changing OrderLine rows in fact table
In our business, we have Orders that are made up of OrderItems. Over time, these Orders can change status (e.g. Received, Challenged, Planned, Completed). During this process, the OrderItems for an ...
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0answers
14 views
Rolling up/aggregating a duration measure in OrderLine fact table
I am starting to model a datawarehouse, and would like some suggestions.
We have Orders and OrderLines. I have read that it is often recommended to model this as one OrderLine fact table at the ...
0
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1answer
63 views
Can a factless fact table be a bridge table?
As for bridge tables, they can be a helper table both for facts and dimensions. But can the factless fact table be a bridge table?
2
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1answer
62 views
Why student attendance is not considered a fact in data warehousing?
In a KimballGroup example student attendance is not considered a fact. Hence it considers this example as forming factless fact table. I don't really understand what is the difference between a fact ...
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0answers
17 views
Building a data cube in a data warehouse through Inmon architecture?
I have been reading about data cubes and Kimball.
Through building a star schema, one can then model a cube using its measures and dimensions of the star schema.
But then there is a different data ...
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0answers
21 views
How can I filter first then show values in BI?
As my title, I'm in this trouble. When I create a BI publisher report, it's show all of value, I just can filter after that.
Can someone tell me know how can I filter values before show it in BI ...
0
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1answer
207 views
Data Warehouse Modeling: Sales Order Charges [closed]
I have two databases systems that I'm trying to dimensional model a sales order business. Both operational data stores have a Sales Order header and detail table. However, one of them has an ...
0
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0answers
169 views
Dimensional Model for CRM Sales Opportunity and Sales Leads: Fact or Dimension?
I'm working for a business lender, and trying to come up with a basic dimensional model around the subject area of loan approvals.
We use a CRM, (Salesforce) and one of the core objects is a (Sales) ...
3
votes
1answer
323 views
Dimensional Modeling of a Loan Approval Process and Fact Grain(s)
Context:
I'm modeling for a lending company and I'm modeling our loan approval process. I have some basic dimensions relative to our business figured out:
Time(day)
Account
Opportunity
...
0
votes
1answer
43 views
Appropriate situation to data warehouse and how to best manage the warehouse? [closed]
I have a query that is on the opening page of our application that takes about 8-10 seconds to load. I've tried all I can to optimize it and I simply cannot make it go any faster (indexed ...
1
vote
1answer
203 views
Error on Datastage when I try to write on AS400
I'm having troubles to operate an ETL process on DataStage.
I have the following error log:
#TABLE#,0: ODBC function "SQLExecute" reported: SQLSTATE = HY000: Native Error Code = -332: Msg = [IBM(...
2
votes
0answers
33 views
How to implement updates from mySQL operational DB to Azure SQL DB for reporting
We have an operational mySQL DB running on AWS for a transactional system and an Azure SQL DB for reporting with PowerBI. Now I'd like to regularly (e.g. every night) do an update of certain tables ...
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0answers
36 views
does a fact table always need to have a field for aggregate?
When I was studying data warehouse modeling, the first thing I came into contact with was the order fact table, and the product, user, date dimension tables.
The order table will have quantity, ...
1
vote
0answers
355 views
Where to build the OLAP cubes? [closed]
I have built a data warehouse with multiple fact tables and dimension tables (with a MySQL server).
Now where could I build the OLAP cubes and write the MDX queries to produce results?
BTW, I have ...
2
votes
1answer
368 views
Run SQL Agent Job 3 times in a Row
How do I execute SQL Agent job 3 times in a row?
We are creating Data Warehouse Project. It ETLs data from Flatfile Legacy Folder, and creates Dim and Fact tables.
SSIS Project Environment Variable (...
0
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1answer
81 views
Do Indexes in the T-SQL Data Warehouse automatically go over and optimize into the SSAS Cube?
Do Indexes in the T-SQL Data Warehouse automatically go over and optimize into the SSAS Cube?
I am reading that applying indexes, will transfer into SSAS. I thought SQL and SSAS are totally different ...
3
votes
3answers
763 views
How to handle schema changes in source systems when running an ETL?
How do people typically handle schema changes in source systems when running an ETL as part of an EDW? For example when a column you were operating on disappears and your ETL breaks.
0
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1answer
45 views
Compare Validate TSQL Data Warehouse to SSAS
How do I compare Data in T-SQL DataWarehouse to SSAS Cube?
I would like to conduct this from SSMS (SQL Server Studio Management Studio).
Example
Select CustomerName from dbo.DimCustomer where ...
-3
votes
1answer
203 views
Kimball Data: Modeling Data as Both Fact and Dimension with View
In Data warehousing, Kimball discusses modeling an insurance policy premium as Both Dimension and Fact.
I have the following table,
create table dbo.DimAutoInsurance
(
DimAutoInsuranceId int ...
3
votes
3answers
2k views
Difference Between a Staging and the Production DWH
I have a general question on a Data Warehouse Architecture. I have heard a lot of a Staging and a Production, so that data should be loaded via SSIS first into a staging dwh and then via SSIS to the ...
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0answers
52 views
How to Represent a VARCHAR Column with XML Data in a Fact Table?
I have SQL Server 2016 environment and I have decided to design a source table with holds some sort of event data as a transactional fact table. The table has about a million rows, and generates about ...
-1
votes
1answer
117 views
Should I place Kimball Data Warehouse in Microsoft Columnstore Index on Premise?
Are Columnstore tables now the vendor default method for Kimball Data warehouse tables with Dim and Facts for On Premise? I know in the cloud, Microsoft automaticaly recommends Azure Data warehouses ...
1
vote
1answer
274 views
When to Disable and Recreate Indexes in Data Warehouse ETL?
We are moving data from Staging Database into Kimball Data Warehouse DB.
I am hearing different ideas regarding when to disable and rebuild indexes.
Stage tables are truncated every day for each new ...
1
vote
2answers
108 views
All Data Transformations via SSIS
Some folks here at my current job have made the decision that all data transformations that go into our database must be done via SSIS. This means that any old code such as views, stored procedures, ...
-2
votes
1answer
258 views
Datawarehouse Staging Tables: Null or Not Null
We are loading data from OLTP into Staging Tables with SSIS, then into Kimball data warehouse with ETL process.
We are inquiring about staging tables, if they should have null/not null constraints. ...
1
vote
1answer
74 views
Data Warehouse: Can a Transaction Table also be a Dimension?
We have a transaction table. Not only does sales team want to analyze by CustomerId or Productid sold, but also by sales amount sold or quantities.
Kimball states, a fact table here can also be a ...
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0answers
22 views
Oracle Best-Buyer-Customer is Wholesale or Retail buyer
I have data warehouse with Fact table Orders, and CustomerDimension, and TimeDimention, and BookDimension.
CREATE TABLE DIM_CUSTOMER(
DIMCUSTID NUMBER(6) PRIMARY KEY,
CustId NUMBER(4) ...
1
vote
1answer
398 views
Best way to capture changes on OLTP for Data Warehouse: Create/Update column or CDC
What is a preferable way to move ETL data into Data Warehouse? Create/Update date on the OLTP application, or Change Data Capture (CDC)?
Given the two are allowed on a system and resourcing is not ...
2
votes
0answers
53 views
Data Warehouse Kimball Interest Rate and Interest Payment Amount
I am modelling a bank account.
Should interest rate be in the DimCheckingAccountId (which shows ProductDimensions, or should it be in fact table, or both). Same with another LoanAccount, should ...
