A database system optimised for reporting, particularly in aggregate. Often, but not always implemented using a star schema.

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Star Schema from Relational Database

I'm a newbie to data warehousing and I've been reading articles and watching videos on the principles but I'm a bit confused as to how I would take the design below and convert it into a star schema. ...
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16 views

Dimension Modelling Senario Data Warehouse Design

I'm looking for some advised on how to model the following scenario in our data warehouse. We have the following entities Staff Mobile Devices Computers Mobile Bills If feels like its simpler ...
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44 views

FastTrack Data Warehouse -E startup parameter

We are running a data warehouse based on the Fast Track architecture. One of the recommendations with Fast Track is to enable the -E parameter at SQL Server startup (increases the number of extents ...
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25 views

How can I DRY up a series of upserts of the same fields from multiple tables?

I have a bunch of tables that all have a storenumber, extracteddate and extractedtime column. I'm doing ETL on these tables and I want to put the last extracted date and time for each store in a ...
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44 views

Why not create ColumnStore index on every single table?

As ColumnStore index improves performance for data warehouse databases, and also since SQL 2104, it is updatable too, why not creating ColumnStore index on every single table? Edit: In SQL 2014 we ...
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24 views

secure specific tables in Data Warehouse

I'm newbie in this domain, I have a project that aim to create java application (Desktop Application) to manage roles based on users profile in a data warehouse. The thing that I'm not able to ...
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32 views

Robust way to build a DWH without downtime

I have a process that build a data warehouse using Postgres. The process runs every day at midnight and works in three steps: Copy the production database (prod) to a temporary database (dwh_tmp) ...
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54 views

Fact Table with blank dimensions

Can I use blank dimensions in a fact table? For instance, total sales in Florida are 200. Sales City State 100 Miami 100 Tampa 200 Florida Reason why is the total for ...
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129 views

How many date dimensions for one fact

About designing star schema: I have three date columns in a fact table fact_table (insert_date, trade_date, close_date ...). And I don't know how many date dimensions should be created? Case 1: Dim ...
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40 views

data validation Datawarehouse ETL

Need a suggestion from Datawarehouse and ETL experts. I have a project which has bunch of fact and dimension table, and we wire the facts using surrogate keys to dimension (religiously following ...
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2answers
92 views

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 ...
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20 views

Should data warehouse provide data for data composition for real time business transactions [closed]

As title, I always had a feeling that data warehouse should only support for data analysis or the like, but shouldn't be used in real time transactions. (eg. being a data source to provide a product ...
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35 views

What is the Difference between Data Transformation vs Transportation?

Is there a difference in meaning between "data transformation" and "data transportation" in ETL process and data warehousing? or both concepts can be used interchangeably in this context? Thanks
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Is REDCap a Data Warehouse Environment?

I working with a web application used to capture research data called The Research Electronic Data Capture (REDCap) system. I am assign to a project to manage the clinical data that are captured in ...
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63 views

FK Issue with Fact Table

I have a Datawarehouse star schema. One Dim table is 'DimTweet'. This contains tweet details. For a selected date I want to be able to display the number of tweets. However, I have a problem in my ...
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65 views

Convert OLTP database to OLAP Datawarehouse

(http://imgur.com/p8Gy67E). Basically I need help to convert that OLTP Model to Data Warehouse in order to be used for further OLAP Cubes. I understand well the difference between the Star Schema and ...
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30 views

Partition Wise Joins in Mysql

Is it possible to create or simulate a partition-wise join in Mysql/Innodb?? Here is a good description of partition-wise joins.... https://blogs.oracle.com/datawarehousing/entry/...
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1answer
74 views

SQL Server : ETL Stage Index

We have a very large staging table (> 80 GB). From our source system we load invoice data in the staging table. From the staging we transform the data and load into DWH/Fact. Every day we delete the ...
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52 views

Data warehouse backup strategy

I have a data warehouse development environment. Just as the production environment. it loads data every night from test OLTP databases. I want a backup every time the load process finishes. What ...
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1answer
56 views

ssis surrogate key in parent child tables

I have two tables Person & Ownership having one to many relationship (each person have many ownerships). Primary Key is person_id of type GUID. I am developing SSIS package to load data from both ...
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1answer
56 views

How to start indexing a new data warehouse

I am building a data warehouse (SQL Server 2012, Kimball Dimensional modeling, 750GB) that will supply data to reports (SSRS), cubes (SSAS) and various datafeeds. I plan to use an index tuning tool (...
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156 views

Incremental extract strategy using SSIS and CDC

I'm looking for a strategy for extracting data from a SQL Server database that is configured for change data capture (CDC) using SSIS. Most of the documentation I have seen around using CDC and SSIS ...
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2answers
124 views

data warehouse automation tool: benefit or bane? [closed]

Today while investigating ETL and data warehouse solutions like Kettle, I came across a new concept (for me) called data warehouse automation tool. I also looked at the white paper here, which ...
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3answers
1k views

Data warehouse server. How do you calculate RAM/CPU specifications?

I am trying to write a spec for a data warehouse server for our planned data warehouse upgrade. As we run virtual servers on VMWare hosts we have the ability to add or remove resources as necessary. ...
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1answer
131 views

How do you index alphanumeric foreign keys on large fact tables?

I have a field that is an alphanumeric field that ideally is a encrypted field for a non-unique identifier. It's used to relate other rather large fact tables in a many-to-many relationship. I do not ...
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2answers
87 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. ...
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86 views

SQL Server Edition for MS 70-463

I just started the MS 70-463 Implementation of warehouse, on the video course the tutor is directing towards SQL Server 2012 Evaluation Edition, but I have already have a SQL Server 2012 Express. Can ...
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112 views

SELECT Causes Performance Issue [closed]

I have a SQL SELECT statement that has joins on 27 of our warehouse tables. Original statement was taking more than an hour everyday so I decided to optimize it. I created some indexes but still it ...
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47 views

What options are there for rebuilds of indexes on large tables for a data warehouse?

I have a bulk loading process that loads millions of records into a few fact tables within a warehouse. Those tables are primarily clustered on time. The non-clustered indexes are in place for how the ...
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38 views

commonly used diagram for ETL

A the title indicates. Am i wondering what is the most commonly used diagram to explain an ETL process? In my case the process is rather linear, would a flowchart suffice? or is a Use-case also ...
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2answers
62 views

SQL Data warehouse and normalization forms

I don't know if it's a simple question but does a data warehouse have different rules when it comes to normalization forms? At the moment I am creating some tables in a data warehouse, and they ...
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324 views

Why should I “Avoid partitioning dimension tables” on SQL Server?

SQL Cat have a list of tips titled Top 10 Best Practices for Building a Large Scale Relational Data Warehouse. Under section 4 - Design dimension tables appropriately they state: Avoid ...
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64 views

Which Azure service for use as data warehouse/analysis store?

We currently have a database running in SQL Server 2012 Standard. We need to export data periodically (a "data dump") of a particular set of data to "a location to be decided" where the client's ...
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2answers
40 views

How can I handle delayed records a month or older on a table clustered on time?

I have a two part question really for anyone working with data warehousing where they have large fact tables. Question 1 Lets say you have a table that has 500 million or more records in it that is ...
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26 views

Database choice for structured big data to be queried with SQL

I have a system that harvests and registers a total of 500K (master table) and 100 million (detail table) into a two table master/detail database, per day. The detail table has around 50 fields, two ...
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25 views

Which Azure Storage / Database Technology to make use of for large scale logging

I am looking into making use of Azure hosting services in order to develop a logging service for our company. Azure has a number of storage options available (I have listed links below). However I am ...
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1answer
92 views

Database modelling : Creating a model for restaurant application which gives statistics

I am working on a server-side application in which users will be able to give ratings and comments to different factors of a 'Restaurant'. What the webapp does is takes all the ratings and creates ...
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2answers
43 views

Should I convert timezones when moving data to a report server/data warehouse

I'm writing an SSIS Package to take data from a production DB to a reports server/data warehouse. The other databases on my reports server are all in Mountain Time but this DB is in UTC should I ...
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2answers
39 views

Non numeric attributes in fact table (to track data source)?

I am creating a data warehouse using star schemas, following the Kimball methodology. One of the rules is only put numeric values in fact tables. I am considering putting an "id" in a fact table, in ...
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1answer
45 views

DSV - SSAS Project - New 2 Columns In Table Change More then I Planned

I encountered a very weird thing. I added in my DWH table 2 new columns but when I refreshed the DSV after adding this to my multidimensional project I saw that more (3) columns have been "changed". ...
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26 views

Fact Table with day grain that has many records that don't change

So I have a daily snapshot fact table that stores financial account balances. Normally, this would be pretty easy, just have a record for every day for every account. My problem is that table would ...
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3answers
30 views

Data Warehouse attribute that describes its timeframe?

I am writing a document about a Data Warehouse system, and would like to know if is there a single word (noun) that describes the DW attribute of how many time it contains? I mean, if a DW contains ...
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194 views

Time out while connecting to the database. Current time out value is 30 seconds

I am installing a repository creation utility on a windows 8 x64 bit system and getting the following error: Time out while connecting to the database. Current time out value is 30 seconds When ...
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1answer
82 views

When to run ETL for dimensions

We have a suite of restaurant web applications that stores data in SQL Server 2012 on database server. We have now started to move data for reporting onto a separate data warehouse server. The data ...
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1answer
138 views

SSAS Calculated Field - rolling sum, for a year of days

I have a fact table storing employee occurrences incurred day over day. I need to have a running sum over the past year of an employee's life. I had, on first pass, done this on ETL, making this "...
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1answer
29 views

How to know if a particular DW project is using Kimball methodology

When I look at the data warehouse/BI/ETL processes in my group, how can I tell if we are using Kimball methodology or not? If I use Slowly Changing Dimensions i.e expire the old record and create a ...
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1answer
93 views

Mixed granularity weeks/months time series data in a data warehouse?

I'm not sure that "anti-aliasing of time series data" is the correct terminology to use, so let me explain: I have some sources of data that are aligned quarterly, mostly to do with quarterly running ...
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10 views

Pentaho getfilename error

I am try to send 20 mail with attachments using pentahi DI, Jobs are like below Get File Names--->Add constants--->Mail But some mails are not send with below error, Thay say files are not ...
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287 views

Time dimension or timestamp in fact table?

Which would you use, and why? A separate time dimension or putting a timestamp in a fact table? Or perhaps both? I am building a data warehouse, and need to represent the time of day that events ...
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1answer
477 views

How do you calculate how much hardware resources you need for a database?

We are in the process of scaling our database servers. I was wondering how should we calculate how much hardware resources we need for our databases? Here is a little bit information about our ...