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

learn more… | top users | synonyms

3
votes
2answers
178 views

how often to run Tablediff

I wonder if it is safe to run the Tablediff tool on a database fairly often? Let's say every 15 or 30 minutes. Also, the Data in the DB is around 100 GB.
3
votes
1answer
241 views

How to represent aggregates in a data warehouse

I am building the dimensional model for a data warehouse (as an exercise for a mini-course I am doing) and I want to build an aggregate to speed up queries. Basically, I want the aggregate to group ...
3
votes
2answers
1k views

ALTER TABLE SWITCH statement failed

ALTER TABLE SWITCH statement failed because column does not have the same ANSI trimming semantics in tables... Does anyone knows how to fix that on already existing table full of data? Well, I've ...
3
votes
1answer
198 views

Should I snowflake or duplicate it across my facts?

I'm building up a data warehouse to be used by SSAS to create cubes on, and I'm debating between two possible schemas. In my warehouse, I've got two different fact tables that tracking daily changes ...
2
votes
2answers
739 views

ETL: extraction strategy for 200 source databases

What is the best extraction strategy for approximately 200 SQL Server 2005 source databases (same schema) for a daily load into a staging area in preparation for data warehouse cleansing, ...
2
votes
2answers
157 views

How to compare the database of a backup from another environment

Has anyone had any luck with taking a backup (approx 30 tables) from an Oracle database's live environment, then loading a test environment with this backup and doing a comparison between the test ...
2
votes
2answers
139 views

Disaster recovery plan - Having multiple servers

I work in an organization where departments are in different buildings. I have a data centre in the main building. All the in-house applications connect to the SQL Server residing in the server in the ...
2
votes
1answer
255 views

Review Technical ETL process for knowledge management

I'm looking for source code and all related component/material to review technical ETL process between source database and Data Warehouse in order to increase my knowledge in technical Business ...
2
votes
2answers
2k views

Reindexing a large database

I have a very large database (millions of rows) which has been indexed. I receive a diff of rows from another source that I need to update in my database. The problem I am facing is that is it ...
2
votes
2answers
274 views

Data warehouse: using day number in Epoch in a date dimension

In Chapter 2 Retail Sales of Ralph Kimball's The Data Warehouse Toolkit, the author describes a date dimension with three fields which appear totally alien to me: Date Key (PK) Date Full Date ...
2
votes
1answer
174 views

What database and setup can handle several million inserts per minute? [closed]

We have come to a point where for a few of our customers' systems, at peak times, events are generated at that crazy rate. That is, millions of new events per minute (between 1M and 2M). The ...
2
votes
1answer
106 views

Advices for modeling facts, time hierarchies based on two conditions

Sorry if my question does not belong to that SE but I tried to find the best place and it ended up here. My problem is this : I've got a table modeled as this in our datawarehouse env. : MYTABLE ...
2
votes
1answer
643 views

Does surrogate key assignment for a fact table require that the source data has natural keys?

Let's say I have a simple OLTP database with orders, products, and customers: And from it, I am building a data mart with an orders fact table, product dimension, customer dimension, and date ...
2
votes
4answers
181 views

SQL Server: Database integration and synchronization

I have n SQL Server databases with the same data schema. On the other hand i have a web application that needs to retrieve, for some entities, the union of the information stored into the n ...
2
votes
1answer
714 views

In star schemas, what should I do when a dimension has a date attribute?

I'm trying to learn about dimensional models and star schemas. Say I have a Sales fact table recording the total sales at retail stores, with, say, four dimensions, Date, Customers, Stores, and ...
2
votes
1answer
184 views

Is dimensional modelling useful for modelling tables of calculations?

I have a set of tables that look a bit like this: Key 1 | Key 2 | Key 3 | Var 1 | Var 2 | Var 3 | ... | Var 200 ------------------------------------------------------------- X | Y | Z | ...
2
votes
1answer
1k views

Tips for Optimizing Oracle Warehouse Builder 11.1 with Oracle DB 10.2

Are there any tips for improving performance of Control Center and Design Center in Oracle Warehouse Builder? At the client side it is very slow to open and refresh Design center and control center ...
2
votes
0answers
110 views

Updating a big replicated Dimension (SQL Server PDW)

We use a SQL Server PDW appliance for our data warehouse. One of the tables in our warehouse is a replicated table with about 20 million rows. As part of our ETL process we need to expire old records ...
2
votes
0answers
123 views

Geographic Hierarchies in a OLAP Cube / Data Warehouse

Are the following geographic hierarchies correct? Do any US/Canadian area codes cross state/province lines? Do any US/Canadian counties cross state/province lines? Are there countries with counties ...
2
votes
0answers
104 views

How to gracefully handle a source database restore from backup in a data warehouse

We are facing a challenging situation with our data warehouse source databases. Frequently these sources databases will be restored from backups. There is a high turnover of data entry persons who ...
1
vote
1answer
254 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 ...
1
vote
2answers
340 views

Data warehouse support tickets

I'm starting to design a data warehouse for a company. The first questions we're trying to resolve are regarding their support ticketing system. My initial schema is as follows Now one of the ...
1
vote
1answer
1k views

How to move data from Primary Data File to other data file without destroying replication

I have one Database which is replicated using transactional replication. Now, I want do spare some data of that database to another partition, because my server running out of disk space. I was ...
1
vote
2answers
293 views

Indexing of Data Warehouse tables?

Maybe I have misunderstood something but I can recall reading an article which said that there is no reason to create non-clustered indexes on very large data warehousing tables? That is because ...
1
vote
1answer
139 views

Conceptual Design of a data warehouse (declaring the grain)

I am trying to design a data warehouse using this example scrubbed data. I need to declare the "grain". I know its the lowest level of detail in the fact table, but I am having a hard time determining ...
1
vote
2answers
184 views

XML Large DataBase is the best? [closed]

Is the best way to implement a large database is XML? Or is there a better way? 1 - reduce the time complexity 2 - Reduce the amount of traffic between the tables And other factors ... Which ...
1
vote
2answers
53 views

Using a data warehouse staging database as a source of operational data

Should you use the staging database within a data warehouse as a source of operational data? ie, is it good practice for other operational (non BI) systems to source their data from this database? ...
1
vote
1answer
70 views

How to dynamically generate rows based on value in a column

I'm attempting to write a query to denormalize some data for integrating to our data warehouse, specifically around generating some time slots. In my source system, I have table that has a start time ...
1
vote
1answer
240 views

Force chain to start immediately after completion instead of on a timer

Is it possible to force an Oracle chain to restart immediately after it finishes executing, instead of on a timer? I have only found ways to do a temporal restart, which doesn't really work for me as ...
1
vote
2answers
406 views

SQL Server 2012 Data Warehousing Overall Flow [closed]

I am studying Data Warehousing in SQL Server 2012 I am attempting to learn the various tools included by practicing on the different tools separately. I have practiced with: AdventureWorks ...
1
vote
2answers
145 views

Designing an Accumulating Snapshot with Repeated Groups, need advise

Situation I need to create a pie chart that has to be able to be represented at the following levels: District, Region, and School. At the student level it has to show the trend of the student over ...
1
vote
1answer
656 views

Design of fact table(s) and dimensions tables for data warehouse

Hi i'm newbie in Datawarehousing, how would you model this in a Data Warehouse: i wish design the Data Warehouse which give the answers of statistics relating to a baseball league For players in ...
1
vote
1answer
33 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 ...
1
vote
1answer
124 views

Fastest mechanism to move data between tables in SQL server

We are building a data warehouse. For some of our target tables, the only way to manage the process correctly is to re-transform all the data every time something changes. Currently we do this using ...
1
vote
1answer
302 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 ...
1
vote
1answer
168 views

Open source tools to manage Data Quality [closed]

Are there open source (or commercial) tools that can report data quality issues in a data warehouse using the Kimball star schema model? It doesn't have to be the silver bullet. I'm just looking for ...
1
vote
1answer
280 views

Oracle Change Data Capture: Unsubscribed column results in change set record

I am using Oracle 11g's Change Data Capture to track changes on a database table. I am using synchronous mode to minimize latency. Here's an example to illustrate my problem: Published_Table ...
1
vote
1answer
534 views

An advice to design a fact table with a scd as a dimension

I have a problem of conception and I would like to get your ideas on how I'll be able to do what I am aiming. My goal is to create a datawarehouse, with three dimensions and one fact table so far. ...
1
vote
0answers
44 views

What type of fact table / loading solution for a reservation system?

I am designing a Data Warehouse with SQL Server 2012 and SSIS. The source system handles hotel reservations. The reservations are split between two tables, header and header line item. The ...
1
vote
1answer
216 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 ...
1
vote
0answers
310 views

sql server 2008 execution plan different on two production servers [closed]

We have two servers running SQL server 2008 R2, with identical databases, where we implemented a datawarehousing solution. The cube processing operation was taking a VERY long time in one of the ...
1
vote
0answers
29 views

Monoblock, Multiblock queries?

What exactly mean the terms monoblock / multiblock queries in data warehouses when talking about materialized views? Does a monoblock query just use one data source (a normal table) while a multiblock ...
0
votes
2answers
2k views

Possible career paths for Oracle Certified Associate (OCA) [closed]

In order to be confident in databases as a entry level job candidate, I completed the OCA certification. Now I want to know what career paths follow this. Can one go into data-mining, BI, or ...
0
votes
2answers
279 views

Can a surrogate key and a primary key be in the same table?

For example we have: Surrogate key: ABC123 Primary key: 1 Name: James Is this legit in a Data Warehouse table?
0
votes
2answers
139 views

Teradata performance statistics

I need some statistics regarding the performance of Teradata, something like with a given hardware, given nodes and given AMPs - a table which has thousands of rows can be read in 't' secs. I need ...
0
votes
1answer
225 views

What are good resources on data modelling for business intelligence? [closed]

We are a SaaS startup offering purchase & procurement solutions. The data model for operational transactions has been created (relational DB). We also want to offer analytics on those transactions ...
0
votes
2answers
109 views

Query to return fields of distinct values per key

In the process of building a data warehouse we are creating some aggregation tables for a reporting engine. We would like to build a single aggregation table from the fact table that can exist as list ...
0
votes
2answers
226 views

SQL Server 2005 replication for a data warehouse

We are trying to implement some kind of Data Warehouse at my current employer. Most of our data is in a SQL Server 2005, but we might also integrate some Access databases and some databases in a SQL ...
0
votes
1answer
104 views

Benefits of using Staging Database while designing Data Warehouse [closed]

I am in process of designing a Data Warehouse Architecture. While exploring various options to Extract data from Production and putting into Data Warehouse, I came across many articles which mainly ...
0
votes
1answer
42 views

How Many Rows om Int and Big Int [closed]

How many rows does datatype int and big int retrieve in their table when you work with fact table in SQL server?