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

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7 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 ...
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20 views

Are there best practices or standardized syntax for writing transformation logic?

This may not be the appropriate forum, but its the closest I could find. I write a lot of source to target mappings for work. These documents just describe the operations/logic/transformations/etc. ...
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1answer
47 views

Load data to datawarehouse via CDC [closed]

As I have surfed in net for moving data to warehouse I found some of the efficient techniques such as: CDC Trigger, DataTime stamp Partitioining. Among which I found the CDC as a better way we can ...
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2answers
183 views

Daily snapshot fact table

I have a list of products per costumer. Costumers can delete or add products to their list. I want to know in each day what is the list of products (and count) by costumer. My first approach is to ...
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0answers
58 views

Handle Duplicate entries in Fact table in Data Cube

We have been constructing data cube for our project in which we are facing a problem like 1 to many relationship in the dimension tables and making entries in fact table (duplication). ...
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0answers
17 views

Best way to perform real time analytics on a growing collection of json file ( very large ) [closed]

I have a very large collection of JSON file (tens of millions) on S3 and I need to have some kind of aggregation (perform continuously as the collection grows). The aggregation is mainly counter ...
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1answer
445 views

creating a report on the mysql jasperReport server

I have mysql local database, in it I have sample data mart. I have installed jasperReport server to my computer. Just using this tool, I want connect to the local mysql database and just create a pdf ...
2
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1answer
61 views

Update Cube data

We are using OLAP in our Project. We are facing a scenario where we need to update the cube with real time data on daily basis. I need some suggestions about an optimal way for updating the data in ...
2
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1answer
80 views

Server roles in SQL Server 2016

There are 3 new server roles in SQL Server 2016: mediumrc largerc xlargerc Any idea what these are for? Google doesn't give any information about these.
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21 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 ...
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1answer
150 views

Migrate Management Data Warehouse to a New Instance

Is there a defined procedure to follow for moving a SQL Server 2012 management data warehouse to a new server\instance? We intend to setup an MDW on a test sql server instance first, but will then ...
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2answers
129 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 ...
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10 views

How to set missing colunms as a null in datastage 9.x.x

I have a sequential file with difference length fields, I want to set missing fields value as a null when I import using datastage, (Not mean set empty fields as a null)
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13 views

Process dimension task is querying the wrong column!

I'm in the process of building a new data warehouse and I am starting out by building a few dimensions. I have created a fairly typical "Date" dimension and that seems ok. Now I am trying to create ...
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3answers
247 views

Is business intelligence (BI) primarily a technical project or a business project? [closed]

I am currently involved in the planning stages for a Business Intelligence (BI) project in our company. We are attempting to understand many facets of the business, and as such the technical side ...
9
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1answer
472 views

Should I disable “auto update statistics” in a data warehousing scenario?

I have 200 GB data warehouse in SQL Server. I have been experiencing really slow execution times for some queries; for example 12 hours for a simple delete query with an inner join. After doing ...
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2answers
58 views

Do valid to/from columns on a fact table make sense?

I recently came across "valid from" and "valid to" columns on a fact table. Obviously this is common for dimensions but I've not seen them on fact tables before and can't find any info suggesting ...
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0answers
47 views

Is there a way to check which views have data? Oracle 11g

I'm undergoing a cleanup process for a data mart design. However, I want to get rid of any views (in the design) which result in having 1 or less rows of data. Instead of manually going through ...
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1answer
26 views

How to load .dat files to oracle database

I have .DAT files extracted from telecom switch. I want to upload this file to an Oracle server using IBM data-stage ETL tool. Unfortunately these files are not readable format. This is a picture ...
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1answer
236 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 ...
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2answers
1k views

Datawarehouse - Dimension, Fact, or Degenerative dimension

I am building a warehouse for a billing system that bills a number of services/utilities on the same invoice, as such I am having real trouble conforming to a recognised design method for the ...
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1answer
17 views

New fact table or new dimension

I have a fact table with 2 dimensions: cohort_id date_id Each record contains the amount of active users from a specific cohort at a particular date - typical structure for the cohort analysis. ...
4
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2answers
90 views

Is it good or bad practice to have a fact table relate to the same dimension table multiple times?

I'm new to DW/BI, and this seems like a pretty basic question, but I can't seem to find a good answer. I have a fact table that would have more than one date associated with it, so I was thinking ...
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0answers
37 views

Best practices to segment people and attributes for advertising database

we have a database where we store people some attributes per person in the following tables: people (id, name, email, phone) people_attributes (id, person_id, attribute_name, attribute_value) ...
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225 views

Calculate sum of a whole column in IBM Datastage without any grouping

I have a table in oracle with salary as one of the columns. I want to calculate the sum of this salary column. It is pretty simple in SQL sum(salary) but I have made some dimensions and facts using ...
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1answer
44 views

How to keep the data warehouse synchronised with the source systems? [closed]

I'm a DBA who is responsible for exporting data from an ERP system for Business Intelligence purposes. The data from ERP system is being sent to the data warehouse and they are used in the ETL ...
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1answer
59 views

Name for intermediate aggregated data [closed]

We have raw data and aggregated data as well as sometimes multiple levels of aggregation between. Is there a name for the data in that intermediate "state" of aggregation? Just like how we have Real ...
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1answer
24 views

Table for actual values

I have a database where logging happens and is processed in a data-warehouse styled environment. This means there are staging cycles where the data comes in and then is processed. For a reporting ...
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4answers
1k views

How do you roll up header-level values on a fact table with line-item granularity?

From what I've read, the recommended granularity for a fact table based on an order header / line item structure is at the line item level. In the process, any additive values that apply only to the ...
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0answers
44 views

Is there value in storing audit fields in a fact table?

I've always stored at least two basic housekeeping fields in all of my dimension and fact tables: DateCreated and DateModified. However, this adds two fairly wide (eight bytes each, in MS SQL) ...
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4answers
501 views

Looking for ideas on maintaining data warehouse in close to real-time - ETL tools, etc

I have done a fair number of traditional data warehouse implementations where the loads were done in a batch-oriented manner, i.e. the data is refreshed nightly or, at most, every few hours. I now ...
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2answers
2k views

Compare two similar Postgres databases for differences

I occasionally download publicly available data sets in the form of Postgres dBs. These datasets are updated/modified/expanded over time by the repository host. Is there a Postgres command or ...
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2answers
146 views

How to prevent users other than DBAs from creating database links

To begin, please keep in mind that I am a very green DBA. I have done prior research and have not really found anything too promising, or maybe it just seems that way because I am still struggling in ...
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2answers
167 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 ...
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1answer
27 views

Data warehouse: Can I tell any details from Source System on delays or blocks? [closed]

I have a MS SQL Server 2012 machine that is acting as our data warehouse currently. We are having issues with long running jobs, and am curious if there is a way to get detailed historical logging on ...
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1answer
87 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 ...
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0answers
69 views

Use trigger to update SCD2 End date and IsCurrentRow flag

I'm implementing a data warehouse that has type 2 slowly changing dimensions. When a change is made to a SCD type 2 column, I need to insert a new row into the dimension for that entity and also ...
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0answers
49 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 | ...
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1answer
102 views

How to change a web application that now needs to become OLTP and OLAP application?

Previously, I did a simple web application for an enterprise client using PHP and MySQL. After some time, it has grown to a point where I realized after talking with people here that I need to treat ...
2
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2answers
181 views

Have a separate database for data warehousing?

I have built a typical web application using PHP and MySQL for enterprise usage. The MySQL database is 3NF as much as possible. However, as time goes by, the requests for the data appear to be more ...
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0answers
77 views

Fact table linked to Slowly Changing Dimension

I'm struggling to understand the best way to model a particular scenario for a data warehouse. I have a Person dimension, and a Tenancy dimension. A person could be on 0, 1 or (rarely) multiple ...
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2answers
276 views

TSQL vs SSIS Lookup

I was trying to find some well performing Tsql equivalents for the SSIS Lookup component. Especially for Fact table loading. After few different query patterns the most obv performed the best: ...
6
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4answers
2k views

Datawarehouse bad practice?

In our Datawarehouse context, we have to update some record in fact tables inside our ETL. One thing we did is to create nonclustered indexes just before the heaviest queries, and drop them ...
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1answer
74 views

How to migrate data of to another sql server

Good day, I have a database running on a virtual machine hosted at our ISP. It is a fairly large database which has about 5GB of data inserted into it every day (network logs). It is partitioned ...
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1answer
97 views

Best way to document Dwh views [closed]

I works in a company that provide Dwh views as an API for external Customers (We use MS-SQL 2008 & 2012). every once in a while we release new views and updates the existing views. We have ...
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0answers
22 views

What known strategies, if any, can I use to validate a Slowly Changing Dimension?

I have a customer dimension in our data warehouse (SSAS 2014 Multidimensional). It is set up as a Type II SCD, with just Start and End Date fields to track changes. (null end date = current). As our ...
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3answers
65 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, ...
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0answers
88 views

Data warehousing: data transfer process too slow with larger batches

I have two primary instances of SQL Server, one for OLTP and one for reporting. The data warehouse for reporting is basically a Type 2 SCD: every table has DWDateStart and DWDateEnd columns and the ...
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0answers
49 views

Physical Table being used a Temp Table in a warehosue. Any advantage?

As I stated in previous posts I've inherited a warehouse based on SQL Server framework. In my continuous review of existing components and the practices adopted by the predecessors I found something ...
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34 views

Accounting - Dimention table in mysql

I am designing a accounting and mini erp system. I use a date dimension table to track all date related data. In oracle we can have many schema for a database. so we could create each schema for ...